Pacemaker operative to deliver impulses of pace signal and sense cardiac response via single conductor of pacemaker lead

ABSTRACT

A pacemaker system includes a drive-sense circuit (DSC) operably coupled to a pacemaker lead. The DSC generates a pace signal including electrical impulses based on a reference signal. The DSC provides the pace signal via the pacemaker lead to an electrically responsive portion of a cardiac conductive system of a subject to facilitate cardiac operation of a cardiovascular system of the subject. The DSC senses, via the pacemaker lead, cardiac electrical activity of the cardiovascular system of the subject that is generated in response to the pace signal and electrically coupled into the pacemaker lead and generates a digital signal that is representative of the cardiac electrical activity of the cardiovascular system of the subject that is sensed via the pacemaker lead. The DSC provides digital information to one or more processing modules that includes and/or is coupled to memory and that provide the reference signal to the DSC.

CROSS REFERENCE TO RELATED PATENTS/PATENT APPLICATIONS Incorporation byReference

The U.S. Utility application Ser. No. 16/891,591, entitled “Arrayoperative to perform distributed/patterned sensing and/or stimulationacross patient bodily section,” filed concurrently on Apr. 3, 2020, ishereby incorporated herein by reference in its entirety and made part ofthe present U.S. Utility Patent Application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable.

BACKGROUND OF THE INVENTION Technical Field of the Invention

This invention relates generally to data communication systems and moreparticularly to sensed data collection and/or communication includingwithin medical and/or therapeutic related applications.

Description of Related Art

Sensors are used in a wide variety of applications ranging from in-homeautomation, to industrial systems, to health care, to transportation,and so on. For example, sensors are placed in bodies, automobiles,airplanes, boats, ships, trucks, motorcycles, cell phones, televisions,touch-screens, industrial plants, appliances, motors, checkout counters,etc. for the variety of applications.

In general, a sensor converts a physical quantity into an electrical oroptical signal. For example, a sensor converts a physical phenomenon,such as a biological condition, a chemical condition, an electriccondition, an electromagnetic condition, a temperature, a magneticcondition, mechanical motion (position, velocity, acceleration, force,pressure), an optical condition, and/or a radioactivity condition, intoan electrical signal.

A sensor includes a transducer, which functions to convert one form ofenergy (e.g., force) into another form of energy (e.g., electricalsignal). There are a variety of transducers to support the variousapplications of sensors. For example, a transducer is capacitor, apiezoelectric transducer, a piezoresistive transducer, a thermaltransducer, a thermal-couple, a photoconductive transducer such as aphotoresistor, a photodiode, and/or phototransistor.

A sensor circuit is coupled to a sensor to provide the sensor with powerand to receive the signal representing the physical phenomenon from thesensor. The sensor circuit includes at least three electricalconnections to the sensor: one for a power supply; another for a commonvoltage reference (e.g., ground); and a third for receiving the signalrepresenting the physical phenomenon. The signal representing thephysical phenomenon will vary from the power supply voltage to ground asthe physical phenomenon changes from one extreme to another (for therange of sensing the physical phenomenon).

The sensor circuits provide the received sensor signals to one or morecomputing devices for processing. A computing device is known tocommunicate data, process data, and/or store data. The computing devicemay be a cellular phone, a laptop, a tablet, a personal computer (PC), awork station, a video game device, a server, and/or a data center thatsupport millions of web searches, stock trades, or on-line purchasesevery hour.

The computing device processes the sensor signals for a variety ofapplications. For example, the computing device processes sensor signalsto determine temperatures of a variety of items in a refrigerated truckduring transit. As another example, the computing device processes thesensor signals to determine a touch on a touchscreen. As yet anotherexample, the computing device processes the sensor signals to determinevarious data points in a production line of a product.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a communicationsystem in accordance with the present invention;

FIG. 2 is a schematic block diagram of an embodiment of a computingdevice in accordance with the present invention;

FIG. 3 is a schematic block diagram of another embodiment of a computingdevice in accordance with the present invention;

FIG. 4 is a schematic block diagram of another embodiment of a computingdevice in accordance with the present invention;

FIG. 5A is a schematic plot diagram of a computing subsystem inaccordance with the present invention;

FIG. 5B is a schematic block diagram of another embodiment of acomputing subsystem in accordance with the present invention;

FIG. 5C is a schematic block diagram of another embodiment of acomputing subsystem in accordance with the present invention;

FIG. 5D is a schematic block diagram of another embodiment of acomputing subsystem in accordance with the present invention;

FIG. 5E is a schematic block diagram of another embodiment of acomputing subsystem in accordance with the present invention;

FIG. 6 is a schematic block diagram of a drive center circuit inaccordance with the present invention;

FIG. 6A is a schematic block diagram of another embodiment of a drivesense circuit in accordance with the present invention;

FIG. 7 is an example of a power signal graph in accordance with thepresent invention;

FIG. 8 is an example of a sensor graph in accordance with the presentinvention;

FIG. 9 is a schematic block diagram of another example of a power signalgraph in accordance with the present invention;

FIG. 10 is a schematic block diagram of another example of a powersignal graph in accordance with the present invention;

FIG. 11 is a schematic block diagram of another example of a powersignal graph in accordance with the present invention;

FIG. 11A is a schematic block diagram of another example of a powersignal graph in accordance with the present invention;

FIG. 12 is a schematic block diagram of an embodiment of a power signalchange detection circuit in accordance with the present invention;

FIG. 13 is a schematic block diagram of another embodiment of adrive-sense circuit in accordance with the present invention;

FIG. 14 is a schematic block diagram of an embodiment of a DSC that isinteractive with an electrode in accordance with the present invention;

FIG. 15 is a schematic block diagram of another embodiment of a DSC thatis interactive with an electrode in accordance with the presentinvention;

FIG. 16A is a schematic block diagram of another embodiment of a DSCconfigured simultaneously to drive and sense a drive signal to anelectrode in accordance with the present invention;

FIG. 16B is a schematic block diagram of another embodiment of a DSCconfigured simultaneously to drive and sense a drive signal to anelectrode in accordance with the present invention;

FIG. 17 is a schematic block diagram of an embodiment of circuitry thatis operative in accordance with one or more pacemaker and/or sensingleads associated with a subject and also includes a pictorialrepresentation of portions of the heart of the subject in accordancewith the present invention;

FIG. 18 is a schematic block diagram showing an example of atypical/normal electrocardiogram (ECG) (alternatively referred to as anEKG) in accordance with the present invention;

FIG. 19 is a schematic block diagram of another embodiment of a DSCconfigured simultaneously to drive and sense a drive signal to anelectrode in accordance with the present invention;

FIG. 20 is a schematic block diagram of an embodiment of multiple DSCsconfigured simultaneously to drive and sense drive signals toelectrodes, respectively, in accordance with the present invention;

FIGS. 21A, 21B, and 21C are schematic block diagrams of embodiments ofdifferent types of pacemakers operable to be serviced by one or moreDSCs in accordance with the present invention;

FIG. 21D is a schematic block diagram of an embodiment of a method forexecution by one or more devices in accordance with the presentinvention;

FIG. 22 is schematic block diagram showing an example of atypical/normal electrocardiogram (ECG) (alternatively referred to as anEKG) showing typical locations of pacing signals and also includes apictorial representation of the relationship between pulse signalimpulse amplitude and pulse width duration that facilitate capture andthat fail to schematic block in accordance with the present invention;

FIGS. 23A and 23B are schematic block diagrams of examples of pacingsignals that may be used in accordance with the present invention;

FIGS. 24A and 24B are schematic block diagrams of other embodiments ofDSCs configured simultaneously to drive and sense drive signals toelectrodes, respectively, in accordance with the present invention;

FIGS. 25A and 25B are schematic block diagrams of embodiments of extrapathways within the heart of a subject that can cause tachycardias andone or more DSCs configured simultaneously to drive and sense drivesignals to electrodes, respectively, capability to provide capability toreduce or eliminate tachycardias within the subject in accordance withthe present invention;

FIGS. 26A and 26B are schematic block diagrams of other embodiments ofDSCs configured simultaneously to drive and sense drive signals toelectrodes, respectively, and that include capability to provide currentsink signals in accordance with the present invention;

FIGS. 27A and 27B are schematic block diagrams of other embodiments ofDSCs configured simultaneously to drive and sense drive signals toelectrodes, respectively, and that include capability to provide currentsource or current sink signals in accordance with the present invention;

FIGS. 28A, 28B, and 28C are schematic block diagrams of otherembodiments of DSCs configured simultaneously to drive and sense drivesignals to electrodes, respectively, and that include capability toprovide differential sensing and/or stimulation across one or morebodily portions of a subject in accordance with the present invention;

FIGS. 29A and 29B are schematic block diagrams of embodiments of sheathsthat are serviced by DSCs that are operative simultaneously to drive andsense drive signals to electrodes, respectively, and that also includescapability to provide single-ended or differential sensing and/orstimulation across one or more bodily portions of a subject inaccordance with the present invention;

FIG. 29C is a schematic block diagram of an embodiment of a sheathshowing connectivity of electrodes to the sensing and/or stimulationpoints of the sheath in accordance with the present invention;

FIG. 29D includes schematic block diagrams of embodiments of sheathsthat are operative to facilitate sensing and/or stimulation across oneor more bodily portions of a subject in accordance with the presentinvention;

FIG. 29E includes schematic block diagrams of embodiments of sheathsthat are operative to facilitate sensing and/or stimulation across oneor more bodily portions of a subject to perform trend tracking based onbilateral symmetry comparative analysis in accordance with the presentinvention;

FIG. 29F includes schematic block diagrams of an embodiment of one ormore sheaths that are operative to facilitate sensing and/or stimulationacross one or more bodily portions of a subject during physical activityincluding adaptation thereof in accordance with the present invention;

FIG. 29G includes schematic block diagrams of an embodiment of a sheaththat is in communication with a control console in accordance with thepresent invention;

FIG. 30 is a schematic block diagram of an embodiment of one or moreelectrodes that are serviced by one or more DSCs that includescapability to provide single-ended or differential sensing and/orstimulation across one or more bodily portions of a subject inaccordance with the present invention;

FIGS. 31A and 31B are schematic block diagrams of embodiments of trendtracking and impedance (Z) monitoring of one or more electrodes toassist in diagnosis of health condition of a subject in accordance withthe present invention;

FIG. 32 is a schematic block diagram of an embodiment of a novelelectrocardiogram (ECG) (alternatively referred to as an EKG) machinethat is serviced by DSCs coupled to ECG stickers via electrodes inaccordance with the present invention; and

FIG. 33 is a schematic block diagram of an embodiment of another methodfor execution by one or more devices in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of a communicationsystem 10 that includes a plurality of computing devices 12-10, one ormore servers 22, one or more databases 24, one or more networks 26, aplurality of drive-sense circuits 28, a plurality of sensors 30, and aplurality of actuators 32. Computing devices 14 include a touchscreen 16with sensors and drive-sensor circuits and computing devices 18 includea touch & tactic screen 20 that includes sensors, actuators, anddrive-sense circuits.

A sensor 30 functions to convert a physical input into an electricaloutput and/or an optical output. The physical input of a sensor may beone of a variety of physical input conditions. For example, the physicalcondition includes one or more of, but is not limited to, acoustic waves(e.g., amplitude, phase, polarization, spectrum, and/or wave velocity);a biological and/or chemical condition (e.g., fluid concentration,level, composition, etc.); an electric condition (e.g., charge, voltage,current, conductivity, permittivity, electric field, which includesamplitude, phase, and/or polarization); a magnetic condition (e.g.,flux, permeability, magnetic field, which amplitude, phase, and/orpolarization); an optical condition (e.g., refractive index,reflectivity, absorption, etc.); a thermal condition (e.g., temperature,flux, specific heat, thermal conductivity, etc.); and a mechanicalcondition (e.g., position, velocity, acceleration, force, strain,stress, pressure, torque, etc.). For example, piezoelectric sensorconverts force or pressure into an electric signal. As another example,a microphone converts audible acoustic waves into electrical signals.

There are a variety of types of sensors to sense the various types ofphysical conditions. Sensor types include, but are not limited to,capacitor sensors, inductive sensors, accelerometers, piezoelectricsensors, light sensors, magnetic field sensors, ultrasonic sensors,temperature sensors, infrared (IR) sensors, touch sensors, proximitysensors, pressure sensors, level sensors, smoke sensors, and gassensors. In many ways, sensors function as the interface between thephysical world and the digital world by converting real world conditionsinto digital signals that are then processed by computing devices for avast number of applications including, but not limited to, medicalapplications, production automation applications, home environmentcontrol, public safety, and so on.

The various types of sensors have a variety of sensor characteristicsthat are factors in providing power to the sensors, receiving signalsfrom the sensors, and/or interpreting the signals from the sensors. Thesensor characteristics include resistance, reactance, powerrequirements, sensitivity, range, stability, repeatability, linearity,error, response time, and/or frequency response. For example, theresistance, reactance, and/or power requirements are factors indetermining drive circuit requirements. As another example, sensitivity,stability, and/or linear are factors for interpreting the measure of thephysical condition based on the received electrical and/or opticalsignal (e.g., measure of temperature, pressure, etc.).

An actuator 32 converts an electrical input into a physical output. Thephysical output of an actuator may be one of a variety of physicaloutput conditions. For example, the physical output condition includesone or more of, but is not limited to, acoustic waves (e.g., amplitude,phase, polarization, spectrum, and/or wave velocity); a magneticcondition (e.g., flux, permeability, magnetic field, which amplitude,phase, and/or polarization); a thermal condition (e.g., temperature,flux, specific heat, thermal conductivity, etc.); and a mechanicalcondition (e.g., position, velocity, acceleration, force, strain,stress, pressure, torque, etc.). As an example, a piezoelectric actuatorconverts voltage into force or pressure. As another example, a speakerconverts electrical signals into audible acoustic waves.

An actuator 32 may be one of a variety of actuators. For example, anactuator 32 is one of a comb drive, a digital micro-mirror device, anelectric motor, an electroactive polymer, a hydraulic cylinder, apiezoelectric actuator, a pneumatic actuator, a screw jack, aservomechanism, a solenoid, a stepper motor, a shape-memory allow, athermal bimorph, and a hydraulic actuator.

The various types of actuators have a variety of actuatorscharacteristics that are factors in providing power to the actuator andsending signals to the actuators for desired performance. The actuatorcharacteristics include resistance, reactance, power requirements,sensitivity, range, stability, repeatability, linearity, error, responsetime, and/or frequency response. For example, the resistance, reactance,and power requirements are factors in determining drive circuitrequirements. As another example, sensitivity, stability, and/or linearare factors for generating the signaling to send to the actuator toobtain the desired physical output condition.

The computing devices 12, 14, and 18 may each be a portable computingdevice and/or a fixed computing device. A portable computing device maybe a social networking device, a gaming device, a cell phone, a smartphone, a digital assistant, a digital music player, a digital videoplayer, a laptop computer, a handheld computer, a tablet, a video gamecontroller, and/or any other portable device that includes a computingcore. A fixed computing device may be a computer (PC), a computerserver, a cable set-top box, a satellite receiver, a television set, aprinter, a fax machine, home entertainment equipment, a video gameconsole, and/or any type of home or office computing equipment. Thecomputing devices 12, 14, and 18 will be discussed in greater detailwith reference to one or more of FIGS. 2-4.

A server 22 is a special type of computing device that is optimized forprocessing large amounts of data requests in parallel. A server 22includes similar components to that of the computing devices 12, 14,and/or 18 with more robust processing modules, more main memory, and/ormore hard drive memory (e.g., solid state, hard drives, etc.). Further,a server 22 is typically accessed remotely; as such it does notgenerally include user input devices and/or user output devices. Inaddition, a server may be a standalone separate computing device and/ormay be a cloud computing device.

A database 24 is a special type of computing device that is optimizedfor large scale data storage and retrieval. A database 24 includessimilar components to that of the computing devices 12, 14, and/or 18with more hard drive memory (e.g., solid state, hard drives, etc.) andpotentially with more processing modules and/or main memory. Further, adatabase 24 is typically accessed remotely; as such it does notgenerally include user input devices and/or user output devices. Inaddition, a database 24 may be a standalone separate computing deviceand/or may be a cloud computing device.

The network 26 includes one more local area networks (LAN) and/or one ormore wide area networks WAN), which may be a public network and/or aprivate network. A LAN may be a wireless-LAN (e.g., Wi-Fi access point,Bluetooth, ZigBee, etc.) and/or a wired network (e.g., Firewire,Ethernet, etc.). A WAN may be a wired and/or wireless WAN. For example,a LAN may be a personal home or business's wireless network and a WAN isthe Internet, cellular telephone infrastructure, and/or satellitecommunication infrastructure.

In an example of operation, computing device 12-1 communicates with aplurality of drive-sense circuits 28, which, in turn, communicate with aplurality of sensors 30. The sensors 30 and/or the drive-sense circuits28 are within the computing device 12-1 and/or external to it. Forexample, the sensors 30 may be external to the computing device 12-1 andthe drive-sense circuits are within the computing device 12-1. Asanother example, both the sensors 30 and the drive-sense circuits 28 areexternal to the computing device 12-1. When the drive-sense circuits 28are external to the computing device, they are coupled to the computingdevice 12-1 via wired and/or wireless communication links as will bediscussed in greater detail with reference to one or more of FIGS.5A-5C.

The computing device 12-1 communicates with the drive-sense circuits 28to; (a) turn them on, (b) obtain data from the sensors (individuallyand/or collectively), (c) instruct the drive sense circuit on how tocommunicate the sensed data to the computing device 12-1, (d) providesignaling attributes (e.g., DC level, AC level, frequency, power level,regulated current signal, regulated voltage signal, regulation of animpedance, frequency patterns for various sensors, different frequenciesfor different sensing applications, etc.) to use with the sensors,and/or (e) provide other commands and/or instructions.

As a specific example, the sensors 30 are distributed along a pipelineto measure flow rate and/or pressure within a section of the pipeline.The drive-sense circuits 28 have their own power source (e.g., battery,power supply, etc.) and are proximally located to their respectivesensors 30. At desired time intervals (milliseconds, seconds, minutes,hours, etc.), the drive-sense circuits 28 provide a regulated sourcesignal or a power signal to the sensors 30. An electrical characteristicof the sensor 30 affects the regulated source signal or power signal,which is reflective of the condition (e.g., the flow rate and/or thepressure) that sensor is sensing.

The drive-sense circuits 28 detect the effects on the regulated sourcesignal or power signals as a result of the electrical characteristics ofthe sensors. The drive-sense circuits 28 then generate signalsrepresentative of change to the regulated source signal or power signalbased on the detected effects on the power signals. The changes to theregulated source signals or power signals are representative of theconditions being sensed by the sensors 30.

The drive-sense circuits 28 provide the representative signals of theconditions to the computing device 12-1. A representative signal may bean analog signal or a digital signal. In either case, the computingdevice 12-1 interprets the representative signals to determine thepressure and/or flow rate at each sensor location along the pipeline.The computing device may then provide this information to the server 22,the database 24, and/or to another computing device for storing and/orfurther processing.

As another example of operation, computing device 12-2 is coupled to adrive-sense circuit 28, which is, in turn, coupled to a senor 30. Thesensor 30 and/or the drive-sense circuit 28 may be internal and/orexternal to the computing device 12-2. In this example, the sensor 30 issensing a condition that is particular to the computing device 12-2. Forexample, the sensor 30 may be a temperature sensor, an ambient lightsensor, an ambient noise sensor, etc. As described above, wheninstructed by the computing device 12-2 (which may be a default settingfor continuous sensing or at regular intervals), the drive-sense circuit28 provides the regulated source signal or power signal to the sensor 30and detects an effect to the regulated source signal or power signalbased on an electrical characteristic of the sensor. The drive-sensecircuit generates a representative signal of the affect and sends it tothe computing device 12-2.

In another example of operation, computing device 12-3 is coupled to aplurality of drive-sense circuits 28 that are coupled to a plurality ofsensors 30 and is coupled to a plurality of drive-sense circuits 28 thatare coupled to a plurality of actuators 32. The generally functionalityof the drive-sense circuits 28 coupled to the sensors 30 in accordancewith the above description.

Since an actuator 32 is essentially an inverse of a sensor in that anactuator converts an electrical signal into a physical condition, whilea sensor converts a physical condition into an electrical signal, thedrive-sense circuits 28 can be used to power actuators 32. Thus, in thisexample, the computing device 12-3 provides actuation signals to thedrive-sense circuits 28 for the actuators 32. The drive-sense circuitsmodulate the actuation signals on to power signals or regulated controlsignals, which are provided to the actuators 32. The actuators 32 arepowered from the power signals or regulated control signals and producethe desired physical condition from the modulated actuation signals.

As another example of operation, computing device 12-x is coupled to adrive-sense circuit 28 that is coupled to a sensor 30 and is coupled toa drive-sense circuit 28 that is coupled to an actuator 32. In thisexample, the sensor 30 and the actuator 32 are for use by the computingdevice 12-x. For example, the sensor 30 may be a piezoelectricmicrophone and the actuator 32 may be a piezoelectric speaker.

FIG. 2 is a schematic block diagram of an embodiment of a computingdevice 12 (e.g., any one of 12-1 through 12-x). The computing device 12includes a core control module 40, one or more processing modules 42,one or more main memories 44, cache memory 46, a video graphicsprocessing module 48, a display 50, an Input-Output (I/O) peripheralcontrol module 52, one or more input interface modules 56, one or moreoutput interface modules 58, one or more network interface modules 60,and one or more memory interface modules 62. A processing module 42 isdescribed in greater detail at the end of the detailed description ofthe invention section and, in an alternative embodiment, has a directionconnection to the main memory 44. In an alternate embodiment, the corecontrol module 40 and the I/O and/or peripheral control module 52 areone module, such as a chipset, a quick path interconnect (QPI), and/oran ultra-path interconnect (UPI).

Each of the main memories 44 includes one or more Random Access Memory(RAM) integrated circuits, or chips. For example, a main memory 44includes four DDR4 (4th generation of double data rate) RAM chips, eachrunning at a rate of 2,400 MHz. In general, the main memory 44 storesdata and operational instructions most relevant for the processingmodule 42. For example, the core control module 40 coordinates thetransfer of data and/or operational instructions from the main memory 44and the memory 64-66. The data and/or operational instructions retrievefrom memory 64-66 are the data and/or operational instructions requestedby the processing module or will most likely be needed by the processingmodule. When the processing module is done with the data and/oroperational instructions in main memory, the core control module 40coordinates sending updated data to the memory 64-66 for storage.

The memory 64-66 includes one or more hard drives, one or more solidstate memory chips, and/or one or more other large capacity storagedevices that, in comparison to cache memory and main memory devices,is/are relatively inexpensive with respect to cost per amount of datastored. The memory 64-66 is coupled to the core control module 40 viathe I/O and/or peripheral control module 52 and via one or more memoryinterface modules 62. In an embodiment, the I/O and/or peripheralcontrol module 52 includes one or more Peripheral Component Interface(PCI) buses to which peripheral components connect to the core controlmodule 40. A memory interface module 62 includes a software driver and ahardware connector for coupling a memory device to the I/O and/orperipheral control module 52. For example, a memory interface 62 is inaccordance with a Serial Advanced Technology Attachment (SATA) port.

The core control module 40 coordinates data communications between theprocessing module(s) 42 and the network(s) 26 via the I/O and/orperipheral control module 52, the network interface module(s) 60, and anetwork card 68 or 70. A network card 68 or 70 includes a wirelesscommunication unit or a wired communication unit. A wirelesscommunication unit includes a wireless local area network (WLAN)communication device, a cellular communication device, a Bluetoothdevice, and/or a ZigBee communication device. A wired communication unitincludes a Gigabit LAN connection, a Firewire connection, and/or aproprietary computer wired connection. A network interface module 60includes a software driver and a hardware connector for coupling thenetwork card to the I/O and/or peripheral control module 52. Forexample, the network interface module 60 is in accordance with one ormore versions of IEEE 802.11, cellular telephone protocols, 10/100/1000Gigabit LAN protocols, etc.

The core control module 40 coordinates data communications between theprocessing module(s) 42 and input device(s) 72 via the input interfacemodule(s) 56 and the I/O and/or peripheral control module 52. An inputdevice 72 includes a keypad, a keyboard, control switches, a touchpad, amicrophone, a camera, etc. An input interface module 56 includes asoftware driver and a hardware connector for coupling an input device tothe I/O and/or peripheral control module 52. In an embodiment, an inputinterface module 56 is in accordance with one or more Universal SerialBus (USB) protocols.

The core control module 40 coordinates data communications between theprocessing module(s) 42 and output device(s) 74 via the output interfacemodule(s) 58 and the I/O and/or peripheral control module 52. An outputdevice 74 includes a speaker, etc. An output interface module 58includes a software driver and a hardware connector for coupling anoutput device to the I/O and/or peripheral control module 52. In anembodiment, an output interface module 56 is in accordance with one ormore audio codec protocols.

The processing module 42 communicates directly with a video graphicsprocessing module 48 to display data on the display 50. The display 50includes an LED (light emitting diode) display, an LCD (liquid crystaldisplay), and/or other type of display technology. The display has aresolution, an aspect ratio, and other features that affect the qualityof the display. The video graphics processing module 48 receives datafrom the processing module 42, processes the data to produce rendereddata in accordance with the characteristics of the display, and providesthe rendered data to the display 50.

FIG. 2 further illustrates sensors 30 and actuators 32 coupled todrive-sense circuits 28, which are coupled to the input interface module56 (e.g., USB port). Alternatively, one or more of the drive-sensecircuits 28 is coupled to the computing device via a wireless networkcard (e.g., WLAN) or a wired network card (e.g., Gigabit LAN). While notshown, the computing device 12 further includes a BIOS (Basic InputOutput System) memory coupled to the core control module 40.

FIG. 3 is a schematic block diagram of another embodiment of a computingdevice 14 that includes a core control module 40, one or more processingmodules 42, one or more main memories 44, cache memory 46, a videographics processing module 48, a touchscreen 16, an Input-Output (I/O)peripheral control module 52, one or more input interface modules 56,one or more output interface modules 58, one or more network interfacemodules 60, and one or more memory interface modules 62. The touchscreen16 includes a touchscreen display 80, a plurality of sensors 30, aplurality of drive-sense circuits (DSC), and a touchscreen processingmodule 82.

Computing device 14 operates similarly to computing device 12 of FIG. 2with the addition of a touchscreen as an input device. The touchscreenincludes a plurality of sensors (e.g., electrodes, capacitor sensingcells, capacitor sensors, inductive sensor, etc.) to detect a proximaltouch of the screen. For example, when one or more fingers touches thescreen, capacitance of sensors proximal to the touch(es) are affected(e.g., impedance changes). The drive-sense circuits (DSC) coupled to theaffected sensors detect the change and provide a representation of thechange to the touchscreen processing module 82, which may be a separateprocessing module or integrated into the processing module 42.

The touchscreen processing module 82 processes the representativesignals from the drive-sense circuits (DSC) to determine the location ofthe touch(es). This information is inputted to the processing module 42for processing as an input. For example, a touch represents a selectionof a button on screen, a scroll function, a zoom in-out function, etc.

FIG. 4 is a schematic block diagram of another embodiment of a computingdevice 18 that includes a core control module 40, one or more processingmodules 42, one or more main memories 44, cache memory 46, a videographics processing module 48, a touch and tactile screen 20, anInput-Output (I/O) peripheral control module 52, one or more inputinterface modules 56, one or more output interface modules 58, one ormore network interface modules 60, and one or more memory interfacemodules 62. The touch and tactile screen 20 includes a touch and tactilescreen display 90, a plurality of sensors 30, a plurality of actuators32, a plurality of drive-sense circuits (DSC), a touchscreen processingmodule 82, and a tactile screen processing module 92.

Computing device 18 operates similarly to computing device 14 of FIG. 3with the addition of a tactile aspect to the screen 20 as an outputdevice. The tactile portion of the screen 20 includes the plurality ofactuators (e.g., piezoelectric transducers to create vibrations,solenoids to create movement, etc.) to provide a tactile feel to thescreen 20. To do so, the processing module creates tactile data, whichis provided to the appropriate drive-sense circuits (DSC) via thetactile screen processing module 92, which may be a stand-aloneprocessing module or integrated into processing module 42. Thedrive-sense circuits (DSC) convert the tactile data into drive-actuatesignals and provide them to the appropriate actuators to create thedesired tactile feel on the screen 20.

FIG. 5A is a schematic plot diagram of a computing subsystem 25 thatincludes a sensed data processing module 65, a plurality ofcommunication modules 61A-x, a plurality of processing modules 42A-x, aplurality of drive sense circuits 28, and a plurality of sensors 1-x,which may be sensors 30 of FIG. 1. The sensed data processing module 65is one or more processing modules within one or more servers 22 and/orone more processing modules in one or more computing devices that aredifferent than the computing devices in which processing modules 42A-xreside.

A drive-sense circuit 28 (or multiple drive-sense circuits), aprocessing module (e.g., 41A), and a communication module (e.g., 61A)are within a common computing device. Each grouping of a drive-sensecircuit(s), processing module, and communication module is in a separatecomputing device. A communication module 61A-x is constructed inaccordance with one or more wired communication protocol and/or one ormore wireless communication protocols that is/are in accordance with theone or more of the Open System Interconnection (OSI) model, theTransmission Control Protocol/Internet Protocol (TCP/IP) model, andother communication protocol module.

In an example of operation, a processing module (e.g., 42A) provides acontrol signal to its corresponding drive-sense circuit 28. Theprocessing module 42 A may generate the control signal, receive it fromthe sensed data processing module 65, or receive an indication from thesensed data processing module 65 to generate the control signal. Thecontrol signal enables the drive-sense circuit 28 to provide a drivesignal to its corresponding sensor. The control signal may furtherinclude a reference signal having one or more frequency components tofacilitate creation of the drive signal and/or interpreting a sensedsignal received from the sensor.

Based on the control signal, the drive-sense circuit 28 provides thedrive signal to its corresponding sensor (e.g., 1) on a drive & senseline. While receiving the drive signal (e.g., a power signal, aregulated source signal, etc.), the sensor senses a physical condition1-x (e.g., acoustic waves, a biological condition, a chemical condition,an electric condition, a magnetic condition, an optical condition, athermal condition, and/or a mechanical condition). As a result of thephysical condition, an electrical characteristic (e.g., impedance,voltage, current, capacitance, inductance, resistance, reactance, etc.)of the sensor changes, which affects the drive signal. Note that if thesensor is an optical sensor, it converts a sensed optical condition intoan electrical characteristic.

The drive-sense circuit 28 detects the effect on the drive signal viathe drive & sense line and processes the affect to produce a signalrepresentative of power change, which may be an analog or digitalsignal. The processing module 42A receives the signal representative ofpower change, interprets it, and generates a value representing thesensed physical condition. For example, if the sensor is sensingpressure, the value representing the sensed physical condition is ameasure of pressure (e.g., x PSI (pounds per square inch)).

In accordance with a sensed data process function (e.g., algorithm,application, etc.), the sensed data processing module 65 gathers thevalues representing the sensed physical conditions from the processingmodules. Since the sensors 1-x may be the same type of sensor (e.g., apressure sensor), may each be different sensors, or a combinationthereof; the sensed physical conditions may be the same, may each bedifferent, or a combination thereof. The sensed data processing module65 processes the gathered values to produce one or more desired results.For example, if the computing subsystem 25 is monitoring pressure alonga pipeline, the processing of the gathered values indicates that thepressures are all within normal limits or that one or more of the sensedpressures is not within normal limits.

As another example, if the computing subsystem 25 is used in amanufacturing facility, the sensors are sensing a variety of physicalconditions, such as acoustic waves (e.g., for sound proofing, soundgeneration, ultrasound monitoring, etc.), a biological condition (e.g.,a bacterial contamination, etc.) a chemical condition (e.g.,composition, gas concentration, etc.), an electric condition (e.g.,current levels, voltage levels, electro-magnetic interference, etc.), amagnetic condition (e.g., induced current, magnetic field strength,magnetic field orientation, etc.), an optical condition (e.g., ambientlight, infrared, etc.), a thermal condition (e.g., temperature, etc.),and/or a mechanical condition (e.g., physical position, force, pressure,acceleration, etc.).

The computing subsystem 25 may further include one or more actuators inplace of one or more of the sensors and/or in addition to the sensors.When the computing subsystem 25 includes an actuator, the correspondingprocessing module provides an actuation control signal to thecorresponding drive-sense circuit 28. The actuation control signalenables the drive-sense circuit 28 to provide a drive signal to theactuator via a drive & actuate line (e.g., similar to the drive & senseline, but for the actuator). The drive signal includes one or morefrequency components and/or amplitude components to facilitate a desiredactuation of the actuator.

In addition, the computing subsystem 25 may include an actuator andsensor working in concert. For example, the sensor is sensing thephysical condition of the actuator. In this example, a drive-sensecircuit provides a drive signal to the actuator and another drive sensesignal provides the same drive signal, or a scaled version of it, to thesensor. This allows the sensor to provide near immediate and continuoussensing of the actuator's physical condition. This further allows forthe sensor to operate at a first frequency and the actuator to operateat a second frequency.

In an embodiment, the computing subsystem is a stand-alone system for awide variety of applications (e.g., manufacturing, pipelines, testing,monitoring, security, etc.). In another embodiment, the computingsubsystem 25 is one subsystem of a plurality of subsystems forming alarger system. For example, different subsystems are employed based ongeographic location. As a specific example, the computing subsystem 25is deployed in one section of a factory and another computing subsystemis deployed in another part of the factory. As another example,different subsystems are employed based function of the subsystems. As aspecific example, one subsystem monitors a city's traffic lightoperation and another subsystem monitors the city's sewage treatmentplants.

Regardless of the use and/or deployment of the computing system, thephysical conditions it is sensing, and/or the physical conditions it isactuating, each sensor and each actuator (if included) is driven andsensed by a single line as opposed to separate drive and sense lines.This provides many advantages including, but not limited to, lower powerrequirements, better ability to drive high impedance sensors, lower lineto line interference, and/or concurrent sensing functions.

FIG. 5B is a schematic block diagram of another embodiment of acomputing subsystem 25 that includes a sensed data processing module 65,a communication module 61, a plurality of processing modules 42A-x, aplurality of drive sense circuits 28, and a plurality of sensors 1-x,which may be sensors 30 of FIG. 1. The sensed data processing module 65is one or more processing modules within one or more servers 22 and/orone more processing modules in one or more computing devices that aredifferent than the computing device, devices, in which processingmodules 42A-x reside.

In an embodiment, the drive-sense circuits 28, the processing modules,and the communication module are within a common computing device. Forexample, the computing device includes a central processing unit thatincludes a plurality of processing modules. The functionality andoperation of the sensed data processing module 65, the communicationmodule 61, the processing modules 42A-x, the drive sense circuits 28,and the sensors 1-x are as discussed with reference to FIG. 5A.

FIG. 5C is a schematic block diagram of another embodiment of acomputing subsystem 25 that includes a sensed data processing module 65,a communication module 61, a processing module 42, a plurality of drivesense circuits 28, and a plurality of sensors 1-x, which may be sensors30 of FIG. 1. The sensed data processing module 65 is one or moreprocessing modules within one or more servers 22 and/or one moreprocessing modules in one or more computing devices that are differentthan the computing device in which the processing module 42 resides.

In an embodiment, the drive-sense circuits 28, the processing module,and the communication module are within a common computing device. Thefunctionality and operation of the sensed data processing module 65, thecommunication module 61, the processing module 42, the drive sensecircuits 28, and the sensors 1-x are as discussed with reference to FIG.5A.

FIG. 5D is a schematic block diagram of another embodiment of acomputing subsystem 25 that includes a processing module 42, a referencesignal circuit 100, a plurality of drive sense circuits 28, and aplurality of sensors 30. The processing module 42 includes a drive-senseprocessing block 104, a drive-sense control block 102, and a referencecontrol block 106. Each block 102-106 of the processing module 42 may beimplemented via separate modules of the processing module, may be acombination of software and hardware within the processing module,and/or may be field programmable modules within the processing module42.

In an example of operation, the drive-sense control block 104 generatesone or more control signals to activate one or more of the drive-sensecircuits 28. For example, the drive-sense control block 102 generates acontrol signal that enables of the drive-sense circuits 28 for a givenperiod of time (e.g., 1 second, 1 minute, etc.). As another example, thedrive-sense control block 102 generates control signals to sequentiallyenable the drive-sense circuits 28. As yet another example, thedrive-sense control block 102 generates a series of control signals toperiodically enable the drive-sense circuits 28 (e.g., enabled onceevery second, every minute, every hour, etc.).

Continuing with the example of operation, the reference control block106 generates a reference control signal that it provides to thereference signal circuit 100. The reference signal circuit 100generates, in accordance with the control signal, one or more referencesignals for the drive-sense circuits 28. For example, the control signalis an enable signal, which, in response, the reference signal circuit100 generates a pre-programmed reference signal that it provides to thedrive-sense circuits 28. In another example, the reference signalcircuit 100 generates a unique reference signal for each of thedrive-sense circuits 28. In yet another example, the reference signalcircuit 100 generates a first unique reference signal for each of thedrive-sense circuits 28 in a first group and generates a second uniquereference signal for each of the drive-sense circuits 28 in a secondgroup.

The reference signal circuit 100 may be implemented in a variety ofways. For example, the reference signal circuit 100 includes a DC(direct current) voltage generator, an AC voltage generator, and avoltage combining circuit. The DC voltage generator generates a DCvoltage at a first level and the AC voltage generator generates an ACvoltage at a second level, which is less than or equal to the firstlevel. The voltage combining circuit combines the DC and AC voltages toproduce the reference signal. As examples, the reference signal circuit100 generates a reference signal similar to the signals shown in FIG. 7,which will be subsequently discussed.

As another example, the reference signal circuit 100 includes a DCcurrent generator, an AC current generator, and a current combiningcircuit. The DC current generator generates a DC current a first currentlevel and the AC current generator generates an AC current at a secondcurrent level, which is less than or equal to the first current level.The current combining circuit combines the DC and AC currents to producethe reference signal.

Returning to the example of operation, the reference signal circuit 100provides the reference signal, or signals, to the drive-sense circuits28. When a drive-sense circuit 28 is enabled via a control signal fromthe drive sense control block 102, it provides a drive signal to itscorresponding sensor 30. As a result of a physical condition, anelectrical characteristic of the sensor is changed, which affects thedrive signal. Based on the detected effect on the drive signal and thereference signal, the drive-sense circuit 28 generates a signalrepresentative of the effect on the drive signal.

The drive-sense circuit provides the signal representative of the effecton the drive signal to the drive-sense processing block 104. Thedrive-sense processing block 104 processes the representative signal toproduce a sensed value 97 of the physical condition (e.g., a digitalvalue that represents a specific temperature, a specific pressure level,etc.). The processing module 42 provides the sensed value 97 to anotherapplication running on the computing device, to another computingdevice, and/or to a server 22.

FIG. 5E is a schematic block diagram of another embodiment of acomputing subsystem 25 that includes a processing module 42, a pluralityof drive sense circuits 28, and a plurality of sensors 30. Thisembodiment is similar to the embodiment of FIG. 5D with thefunctionality of the drive-sense processing block 104, a drive-sensecontrol block 102, and a reference control block 106 shown in greaterdetail. For instance, the drive-sense control block 102 includesindividual enable/disable blocks 102-1 through 102-y. An enable/disableblock functions to enable or disable a corresponding drive-sense circuitin a manner as discussed above with reference to FIG. 5D.

The drive-sense processing block 104 includes variance determiningmodules 104-1 a through y and variance interpreting modules 104-2 athrough y. For example, variance determining module 104-1 a receives,from the corresponding drive-sense circuit 28, a signal representativeof a physical condition sensed by a sensor. The variance determiningmodule 104-1 a functions to determine a difference from the signalrepresenting the sensed physical condition with a signal representing aknown, or reference, physical condition. The variance interpretingmodule 104-1 b interprets the difference to determine a specific valuefor the sensed physical condition.

As a specific example, the variance determining module 104-1 a receivesa digital signal of 1001 0110 (150 in decimal) that is representative ofa sensed physical condition (e.g., temperature) sensed by a sensor fromthe corresponding drive-sense circuit 28. With 8-bits, there are 2⁸(256) possible signals representing the sensed physical condition.Assume that the units for temperature is Celsius and a digital value of0100 0000 (64 in decimal) represents the known value for 25 degreeCelsius. The variance determining module 104-b 1 determines thedifference between the digital signal representing the sensed value(e.g., 1001 0110, 150 in decimal) and the known signal value of (e.g.,0100 0000, 64 in decimal), which is 0011 0000 (86 in decimal). Thevariance determining module 104-b 1 then determines the sensed valuebased on the difference and the known value. In this example, the sensedvalue equals 25+86*(100/256)=25+33.6=58.6 degrees Celsius.

FIG. 6 is a schematic block diagram of a drive center circuit 28-acoupled to a sensor 30. The drive sense-sense circuit 28 includes apower source circuit 110 and a power signal change detection circuit112. The sensor 30 includes one or more transducers that have varyingelectrical characteristics (e.g., capacitance, inductance, impedance,current, voltage, etc.) based on varying physical conditions 114 (e.g.,pressure, temperature, biological, chemical, etc.), or vice versa (e.g.,an actuator).

The power source circuit 110 is operably coupled to the sensor 30 and,when enabled (e.g., from a control signal from the processing module 42,power is applied, a switch is closed, a reference signal is received,etc.) provides a power signal 116 to the sensor 30. The power sourcecircuit 110 may be a voltage supply circuit (e.g., a battery, a linearregulator, an unregulated DC-to-DC converter, etc.) to produce avoltage-based power signal, a current supply circuit (e.g., a currentsource circuit, a current mirror circuit, etc.) to produce acurrent-based power signal, or a circuit that provide a desired powerlevel to the sensor and substantially matches impedance of the sensor.The power source circuit 110 generates the power signal 116 to include aDC (direct current) component and/or an oscillating component.

When receiving the power signal 116 and when exposed to a condition 114,an electrical characteristic of the sensor affects 118 the power signal.When the power signal change detection circuit 112 is enabled, itdetects the affect 118 on the power signal as a result of the electricalcharacteristic of the sensor. For example, the power signal is a 1.5voltage signal and, under a first condition, the sensor draws 1 milliampof current, which corresponds to an impedance of 1.5 K Ohms. Under asecond conditions, the power signal remains at 1.5 volts and the currentincreases to 1.5 milliamps. As such, from condition 1 to condition 2,the impedance of the sensor changed from 1.5 K Ohms to 1 K Ohms. Thepower signal change detection circuit 112 determines this change andgenerates a representative signal 120 of the change to the power signal.

As another example, the power signal is a 1.5 voltage signal and, undera first condition, the sensor draws 1 milliamp of current, whichcorresponds to an impedance of 1.5 K Ohms. Under a second conditions,the power signal drops to 1.3 volts and the current increases to 1.3milliamps. As such, from condition 1 to condition 2, the impedance ofthe sensor changed from 1.5 K Ohms to 1 K Ohms. The power signal changedetection circuit 112 determines this change and generates arepresentative signal 120 of the change to the power signal.

The power signal 116 includes a DC component 122 and/or an oscillatingcomponent 124 as shown in FIG. 7. The oscillating component 124 includesa sinusoidal signal, a square wave signal, a triangular wave signal, amultiple level signal (e.g., has varying magnitude over time withrespect to the DC component), and/or a polygonal signal (e.g., has asymmetrical or asymmetrical polygonal shape with respect to the DCcomponent). Note that the power signal is shown without affect from thesensor as the result of a condition or changing condition.

In an embodiment, power generating circuit 110 varies frequency of theoscillating component 124 of the power signal 116 so that it can betuned to the impedance of the sensor and/or to be off-set in frequencyfrom other power signals in a system. For example, a capacitancesensor's impedance decreases with frequency. As such, if the frequencyof the oscillating component is too high with respect to thecapacitance, the capacitor looks like a short and variances incapacitances will be missed. Similarly, if the frequency of theoscillating component is too low with respect to the capacitance, thecapacitor looks like an open and variances in capacitances will bemissed.

In an embodiment, the power generating circuit 110 varies magnitude ofthe DC component 122 and/or the oscillating component 124 to improveresolution of sensing and/or to adjust power consumption of sensing. Inaddition, the power generating circuit 110 generates the drive signal110 such that the magnitude of the oscillating component 124 is lessthan magnitude of the DC component 122.

FIG. 6A is a schematic block diagram of a drive center circuit 28-a 1coupled to a sensor 30. The drive sense-sense circuit 28-a 1 includes asignal source circuit 111, a signal change detection circuit 113, and apower source 115. The power source 115 (e.g., a battery, a power supply,a current source, etc.) generates a voltage and/or current that iscombined with a signal 117, which is produced by the signal sourcecircuit 111. The combined signal is supplied to the sensor 30.

The signal source circuit 111 may be a voltage supply circuit (e.g., abattery, a linear regulator, an unregulated DC-to-DC converter, etc.) toproduce a voltage-based signal 117, a current supply circuit (e.g., acurrent source circuit, a current mirror circuit, etc.) to produce acurrent-based signal 117, or a circuit that provide a desired powerlevel to the sensor and substantially matches impedance of the sensor.The signal source circuit 111 generates the signal 117 to include a DC(direct current) component and/or an oscillating component.

When receiving the combined signal (e.g., signal 117 and power from thepower source) and when exposed to a condition 114, an electricalcharacteristic of the sensor affects 119 the signal. When the signalchange detection circuit 113 is enabled, it detects the affect 119 onthe signal as a result of the electrical characteristic of the sensor.

FIG. 8 is an example of a sensor graph that plots an electricalcharacteristic versus a condition. The sensor has a substantially linearregion in which an incremental change in a condition produces acorresponding incremental change in the electrical characteristic. Thegraph shows two types of electrical characteristics: one that increasesas the condition increases and the other that decreases and thecondition increases. As an example of the first type, impedance of atemperature sensor increases and the temperature increases. As anexample of a second type, a capacitance touch sensor decreases incapacitance as a touch is sensed.

FIG. 9 is a schematic block diagram of another example of a power signalgraph in which the electrical characteristic or change in electricalcharacteristic of the sensor is affecting the power signal. In thisexample, the effect of the electrical characteristic or change inelectrical characteristic of the sensor reduced the DC component but hadlittle to no effect on the oscillating component. For example, theelectrical characteristic is resistance. In this example, the resistanceor change in resistance of the sensor decreased the power signal,inferring an increase in resistance for a relatively constant current.

FIG. 10 is a schematic block diagram of another example of a powersignal graph in which the electrical characteristic or change inelectrical characteristic of the sensor is affecting the power signal.In this example, the effect of the electrical characteristic or changein electrical characteristic of the sensor reduced magnitude of theoscillating component but had little to no effect on the DC component.For example, the electrical characteristic is impedance of a capacitorand/or an inductor. In this example, the impedance or change inimpedance of the sensor decreased the magnitude of the oscillatingsignal component, inferring an increase in impedance for a relativelyconstant current.

FIG. 11 is a schematic block diagram of another example of a powersignal graph in which the electrical characteristic or change inelectrical characteristic of the sensor is affecting the power signal.In this example, the effect of the electrical characteristic or changein electrical characteristic of the sensor shifted frequency of theoscillating component but had little to no effect on the DC component.For example, the electrical characteristic is reactance of a capacitorand/or an inductor. In this example, the reactance or change inreactance of the sensor shifted frequency of the oscillating signalcomponent, inferring an increase in reactance (e.g., sensor isfunctioning as an integrator or phase shift circuit).

FIG. 11A is a schematic block diagram of another example of a powersignal graph in which the electrical characteristic or change inelectrical characteristic of the sensor is affecting the power signal.In this example, the effect of the electrical characteristic or changein electrical characteristic of the sensor changes the frequency of theoscillating component but had little to no effect on the DC component.For example, the sensor includes two transducers that oscillate atdifferent frequencies. The first transducer receives the power signal ata frequency of f₁ and converts it into a first physical condition. Thesecond transducer is stimulated by the first physical condition tocreate an electrical signal at a different frequency f₂. In thisexample, the first and second transducers of the sensor change thefrequency of the oscillating signal component, which allows for moregranular sensing and/or a broader range of sensing.

FIG. 12 is a schematic block diagram of an embodiment of a power signalchange detection circuit 112 receiving the affected power signal 118 andthe power signal 116 as generated to produce, therefrom, the signalrepresentative 120 of the power signal change. The affect 118 on thepower signal is the result of an electrical characteristic and/or changein the electrical characteristic of a sensor; a few examples of theaffects are shown in FIGS. 8-11A.

In an embodiment, the power signal change detection circuit 112 detect achange in the DC component 122 and/or the oscillating component 124 ofthe power signal 116. The power signal change detection circuit 112 thengenerates the signal representative 120 of the change to the powersignal based on the change to the power signal. For example, the changeto the power signal results from the impedance of the sensor and/or achange in impedance of the sensor. The representative signal 120 isreflective of the change in the power signal and/or in the change in thesensor's impedance.

In an embodiment, the power signal change detection circuit 112 isoperable to detect a change to the oscillating component at a frequency,which may be a phase shift, frequency change, and/or change in magnitudeof the oscillating component. The power signal change detection circuit112 is also operable to generate the signal representative of the changeto the power signal based on the change to the oscillating component atthe frequency. The power signal change detection circuit 112 is furtheroperable to provide feedback to the power source circuit 110 regardingthe oscillating component. The feedback allows the power source circuit110 to regulate the oscillating component at the desired frequency,phase, and/or magnitude.

FIG. 13 is a schematic block diagram of another embodiment of a drivesense circuit 28-b includes a change detection circuit 150, a regulationcircuit 152, and a power source circuit 154. The drive-sense circuit28-b is coupled to the sensor 30, which includes a transducer that hasvarying electrical characteristics (e.g., capacitance, inductance,impedance, current, voltage, etc.) based on varying physical conditions114 (e.g., pressure, temperature, biological, chemical, etc.).

The power source circuit 154 is operably coupled to the sensor 30 and,when enabled (e.g., from a control signal from the processing module 42,power is applied, a switch is closed, a reference signal is received,etc.) provides a power signal 158 to the sensor 30. The power sourcecircuit 154 may be a voltage supply circuit (e.g., a battery, a linearregulator, an unregulated DC-to-DC converter, etc.) to produce avoltage-based power signal or a current supply circuit (e.g., a currentsource circuit, a current mirror circuit, etc.) to produce acurrent-based power signal. The power source circuit 154 generates thepower signal 158 to include a DC (direct current) component and anoscillating component.

When receiving the power signal 158 and when exposed to a condition 114,an electrical characteristic of the sensor affects 160 the power signal.When the change detection circuit 150 is enabled, it detects the affect160 on the power signal as a result of the electrical characteristic ofthe sensor 30. The change detection circuit 150 is further operable togenerate a signal 120 that is representative of change to the powersignal based on the detected effect on the power signal.

The regulation circuit 152, when its enabled, generates regulationsignal 156 to regulate the DC component to a desired DC level and/orregulate the oscillating component to a desired oscillating level (e.g.,magnitude, phase, and/or frequency) based on the signal 120 that isrepresentative of the change to the power signal. The power sourcecircuit 154 utilizes the regulation signal 156 to keep the power signalat a desired setting 158 regardless of the electrical characteristic ofthe sensor. In this manner, the amount of regulation is indicative ofthe affect the electrical characteristic had on the power signal.

In an example, the power source circuit 158 is a DC-DC converteroperable to provide a regulated power signal having DC and ACcomponents. The change detection circuit 150 is a comparator and theregulation circuit 152 is a pulse width modulator to produce theregulation signal 156. The comparator compares the power signal 158,which is affected by the sensor, with a reference signal that includesDC and AC components. When the electrical characteristics is at a firstlevel (e.g., a first impedance), the power signal is regulated toprovide a voltage and current such that the power signal substantiallyresembles the reference signal.

When the electrical characteristics changes to a second level (e.g., asecond impedance), the change detection circuit 150 detects a change inthe DC and/or AC component of the power signal 158 and generates therepresentative signal 120, which indicates the changes. The regulationcircuit 152 detects the change in the representative signal 120 andcreates the regulation signal to substantially remove the effect on thepower signal. The regulation of the power signal 158 may be done byregulating the magnitude of the DC and/or AC components, by adjustingthe frequency of AC component, and/or by adjusting the phase of the ACcomponent.

With respect to the operation of various drive-sense circuits asdescribed herein and/or their equivalents, note that the operation ofsuch a drive-sense circuit is operable simultaneously to drive and sensea signal via a single line. In comparison to switched, time-divided,time-multiplexed, etc. operation in which there is switching betweendriving and sensing (e.g., driving at first time, sensing at secondtime, etc.) of different respective signals at separate and distincttimes, the drive-sense circuit is operable simultaneously to performboth driving and sensing of a signal. In some examples, suchsimultaneous driving and sensing is performed via a single line using adrive-sense circuit.

In addition, other alternative implementations of various drive-sensecircuits (DSCs) are described in U.S. Utility patent application Ser.No. 16/113,379, entitled “DRIVE SENSE CIRCUIT WITH DRIVE-SENSE LINE,”filed Aug. 27, 2018, pending. Any instantiation of a drive-sense circuitas described herein may also be implemented using any of the variousimplementations of various drive-sense circuits (DSCs) described in U.S.Utility patent application Ser. No. 16/113,379.

In addition, note that the one or more signals provided from adrive-sense circuit (DSC) may be of any of a variety of types. Forexample, such a signal may be based on encoding of one or more bits togenerate one or more coded bits used to generate modulation data (orgenerally, data). For example, a device is configured to perform forwarderror correction (FEC) and/or error checking and correction (ECC) codeof one or more bits to generate one or more coded bits. Examples of FECand/or ECC may include turbo code, convolutional code, trellis codedmodulation (TCM), turbo trellis coded modulation (TTCM), low densityparity check (LDPC) code, Reed-Solomon (RS) code, BCH (Bose andRay-Chaudhuri, and Hocquenghem) code, binary convolutional code (BCC),Cyclic Redundancy Check (CRC), and/or any other type of ECC and/or FECcode and/or combination thereof, etc. Note that more than one type ofECC and/or FEC code may be used in any of various implementationsincluding concatenation (e.g., first ECC and/or FEC code followed bysecond ECC and/or FEC code, etc. such as based on an inner code/outercode architecture, etc.), parallel architecture (e.g., such that firstECC and/or FEC code operates on first bits while second ECC and/or FECcode operates on second bits, etc.), and/or any combination thereof.

Also, the one or more coded bits may then undergo modulation or symbolmapping to generate modulation symbols (e.g., the modulation symbols mayinclude data intended for one or more recipient devices, components,elements, etc.). Note that such modulation symbols may be generatedusing any of various types of modulation coding techniques. Examples ofsuch modulation coding techniques may include binary phase shift keying(BPSK), quadrature phase shift keying (QPSK), 8-phase shift keying(PSK), 16 quadrature amplitude modulation (QAM), 32 amplitude and phaseshift keying (APSK), etc., uncoded modulation, and/or any other desiredtypes of modulation including higher ordered modulations that mayinclude even greater number of constellation points (e.g., 1024 QAM,etc.).

In addition, note that a signal provided from a DSC may be of a uniquefrequency that is different from signals provided from other DSCs. Also,a signal provided from a DSC may include multiple frequenciesindependently or simultaneously. The frequency of the signal can behopped on a pre-arranged pattern. In some examples, a handshake isestablished between one or more DSCs and one or more processing modules(e.g., one or more controllers) such that the one or more DSC is/aredirected by the one or more processing modules regarding which frequencyor frequencies and/or which other one or more characteristics of the oneor more signals to use at one or more respective times and/or in one ormore particular situations.

With respect to any signal that is driven and simultaneously detected bya DSC, note that any additional signal that is coupled into a line, anelectrode, a touch sensor, a bus, a communication link, a battery, aload, an electrical coupling or connection, etc. associated with thatDSC is also detectable. For example, a DSC that is associated with sucha line, an electrode, a touch sensor, a bus, a communication link, aload, an electrical coupling or connection, a pacemaker lead, a sensinglead, a lead that is operable to facilitate both pacemaker and sensingfunctionality, etc. is configured to detect any signal from one or moreother lines, electrodes, touch sensors, buses, communication links,loads, electrical couplings or connections, etc. that get coupled intothat line, electrode, touch sensor, bus, communication link, electricalcoupling or connection, a pacemaker lead, a sensing lead, a lead that isoperable to perform both pacemaker and sensing functionality, etc.

Note that the different respective signals that are driven andsimultaneously sensed by one or more DSCs may be are differentiated fromone another. Appropriate filtering and processing can identify thevarious signals given their differentiation, orthogonality to oneanother, difference in frequency, etc. Other examples described hereinand their equivalents operate using any of a number of differentcharacteristics other than or in addition to frequency.

Moreover, with respect to any embodiment, diagram, example, etc. thatincludes more than one DSC, note that the DSCs may be implemented in avariety of manners. For example, all of the DSCs may be of the sametype, implementation, configuration, etc. In another example, the firstDSC may be of a first type, implementation, configuration, etc., and asecond DSC may be of a second type, implementation, configuration, etc.that is different than the first DSC. Considering a specific example, afirst DSC may be implemented to detect change of impedance associatedwith a line, an electrode, a touch sensor, a bus, a communication link,an electrical coupling or connection, etc. associated with that firstDSC, while a second DSC may be implemented to detect change of voltageassociated with a line, an electrode, a touch sensor, a bus, acommunication link, an electrical coupling or connection, etc.associated with that second DSC. In addition, note that a third DSC maybe implemented to detect change of a current associated with a line, anelectrode, a touch sensor, a bus, a communication link, an electricalcoupling or connection, etc. associated with that DSC. In general, whilea common reference may be used generally to show a DSC or multipleinstantiations of a DSC within a given embodiment, diagram, example,etc., note that any particular DSC may be implemented in accordance withany manner as described herein, such as described in U.S. Utility patentapplication Ser. No. 16/113,379, etc. and/or their equivalents.

Note that certain of the diagrams herein show a computing device (e.g.,alternatively referred to as device; the terms computing device anddevice may be used interchangeably) that may include or be coupled toone or more processing modules. In certain instances, the one or moreprocessing modules is configured to communicate with and interact withone or more other devices including one or more of DSCs, one or morecomponents associated with a DSC such as one or more of a line, anelectrode, a touch sensor, a bus, a communication link, a load, anelectrical coupling or connection, a sensing and/or stimulation pointsuch as located at the end of an electrode that may be applied to andassociated with a subject (e.g., a user, person, a patient, etc.), asensing and/or stimulation point such as located within a sheath thatmay be applied to and associated with a subject (e.g., a user, person, apatient, etc.), a pacemaker lead, a sensing lead, a lead that isoperable to facilitate both pacemaker and sensing functionality, etc.Note that reference to a subject herein may be used interchangeably withthe user, person, patient, etc. generally speaking, many of the variousaspects, embodiments, and/or examples of the invention (and/or theirequivalents) provide means by which sensing and/or stimulation may beperformed using one or more DSCs and one or more of electrodes, whichmay be implemented in a variety of different ways including one or moreof a pacemaker lead, a sensing lead, a lead that is operable tofacilitate both pacemaker and sensing functionality, etc. to facilitatesuch sensing and/or stimulation of one or more ugly portions of asubject.

Note that any such implementation of one or more processing modules mayinclude integrated memory and/or be coupled to other memory. At leastsome of the memory stores operational instructions to be executed by theone or more processing modules. In addition, note that the one or moreprocessing modules may interface with one or more other devices,components, elements, etc. via one or more communication links,networks, communication pathways, channels, etc. (e.g., such as via oneor more communication interfaces of the device, such as may beintegrated into the one or more processing modules or be implemented asa separate component, circuitry, etc.).

In addition, when a DSC is implemented to communicate with and interactwith another element, the DSC is configured simultaneously to transmitand receive one or more signals with the element. For example, a DSC isconfigured simultaneously to sense (e.g., including to sense change of)and to drive one or more signals to the one element. During transmissionof a signal from a DSC, that same DSC is configured simultaneously tosense the signal being transmitted from the DSC including any changethereof including any other signal may be coupled into the signal thatis being transmitted from the DSC.

In addition, while many examples, embodiments, diagrams, etc. hereininclude one or more DSCs (e.g., coupled to one or more processingmodules and one or more electrodes), note that any instantiation of aDSC may alternatively be implemented using a channel drive circuitry, anAnalog Front End (AFE) that includes analog to digital and/or digital toanalog conversion capability, etc. within alternative embodiments.

FIG. 14 is a schematic block diagram of an embodiment 1400 of a DSC thatis interactive with an electrode in accordance with the presentinvention. Similar to other diagrams, examples, embodiments, etc.herein, the DSC 28-a 2 of this diagram is in communication with one ormore processing modules 42. The DSC 28-a 2 is configured to provide asignal (e.g., a power signal, an electrode signal, transmit signal, amonitoring signal, etc.) to the electrode 1410 via a single line andsimultaneously to sense that signal via the single line. In someexamples, sensing the signal includes detection of an electricalcharacteristic of the electrode that is based on a response of theelectrode 1410 to that signal. Examples of such an electricalcharacteristic may include detection of an impedance of the electrode1410 such as a change of capacitance of the electrode 1410, detection ofone or more signals coupled into the electrode 1410 such as from one ormore other electrodes, and/or other electrical characteristics.

This embodiment of a DSC 28-a 2 includes a current source 110-1 and apower signal change detection circuit 112-a 1. The power signal changedetection circuit 112-a 1 includes a power source reference circuit 130and a comparator 132. In some examples, the comparator 132 isalternatively be implemented as an operational amplifier. The currentsource 110-1 may be an independent current source, a dependent currentsource, a current mirror circuit, etc.

In an example of operation, the power source reference circuit 130provides a current reference 134 with DC and oscillating components tothe current source 110-1. The current source generates a current as thepower signal 116 based on the current reference 134. An electricalcharacteristic of the electrode 1410 has an effect on the current powersignal 116. For example, if the impedance of the electrode 1410decreases and the current power signal 116 remains substantiallyunchanged, the voltage across the electrode 1410 is decreased.

The comparator 132 compares the current reference 134 with the affectedpower signal 118 to produce the signal 120 that is representative of thechange to the power signal. For example, the current reference signal134 corresponds to a given current (I) times a given impedance (Z). Thecurrent reference generates the power signal to produce the givencurrent (I). If the impedance of the electrode 1410 substantiallymatches the given impedance (Z), then the comparator's output isreflective of the impedances substantially matching. If the impedance ofthe electrode 1410 is greater than the given impedance (Z), then thecomparator's output is indicative of how much greater the impedance ofthe electrode 1410 is than that of the given impedance (Z). If theimpedance of the electrode 1410 is less than the given impedance (Z),then the comparator's output is indicative of how much less theimpedance of the electrode 1410 is than that of the given impedance (Z).

FIG. 15 is a schematic block diagram of another embodiment 1500 of a DSCthat is interactive with an electrode in accordance with the presentinvention. Similar to other diagrams, examples, embodiments, etc.herein, the DSC 28-a 3 of this diagram is in communication with one ormore processing modules 42. Similar to the previous diagram, althoughproviding a different embodiment of the DSC, the DSC 28-a 3 isconfigured to provide a signal to the electrode 1410 via a single lineand simultaneously to sense that signal via the single line. In someexamples, sensing the signal includes detection of an electricalcharacteristic of the electrode 1410 that is based on a response of theelectrode 1410 to that signal. Examples of such an electricalcharacteristic may include detection of an impedance of the electrode1410 such as a change of capacitance of the electrode 1410, detection ofone or more signals coupled into the electrode 1410 such as from one ormore other electrodes, and/or other electrical characteristics.

This embodiment of a DSC 28-a 3 includes a voltage source 110-2 and apower signal change detection circuit 112-a 2. The power signal changedetection circuit 112-a 2 includes a power source reference circuit130-2 and a comparator 132-2. The voltage source 110-2 may be a battery,a linear regulator, a DC-DC converter, etc.

In an example of operation, the power source reference circuit 130-2provides a voltage reference 136 with DC and oscillating components tothe voltage source 110-2. The voltage source generates a voltage as thepower signal 116 based on the voltage reference 136. An electricalcharacteristic of the electrode 1410 has an effect on the voltage powersignal 116. For example, if the impedance of the electrode 1410decreases and the voltage power signal 116 remains substantiallyunchanged, the current through the electrode 1410 is increased.

The comparator 132 compares the voltage reference 136 with the affectedpower signal 118 to produce the signal 120 that is representative of thechange to the power signal. For example, the voltage reference signal134 corresponds to a given voltage (V) divided by a given impedance (Z).The voltage reference generates the power signal to produce the givenvoltage (V). If the impedance of the electrode 1410 substantiallymatches the given impedance (Z), then the comparator's output isreflective of the impedances substantially matching. If the impedance ofthe electrode 1410 is greater than the given impedance (Z), then thecomparator's output is indicative of how much greater the impedance ofthe electrode 1410 is than that of the given impedance (Z). If theimpedance of the electrode 1410 is less than the given impedance (Z),then the comparator's output is indicative of how much less theimpedance of the electrode 1410 is than that of the given impedance (Z).

With respect to many of the following diagrams, one or more processingmodules 42, which includes and/or is coupled to memory, is configured tocommunicate and interact with one or more DSCs 28 that are coupled toone or more electrodes. Note that the electrodes may be implemented fordelivery of one or more signals including for pacing signaling (e.g.,such as with respect to a cardiac implemented pacemaker to assist asubject in controlling heart function) or stimulation and/or sensingsuch as with respect to detecting electrical activity such as cardiacactivity, impedance sensing, etc. In other examples, the electrodes arecoupled to a panel or a touchscreen display such as may be implementedwithin a touch sensor device (TSD)(with or without displayfunctionality). In certain of the diagrams, the DSCs 28 are shown asinterfacing with electrodes of a panel or touchscreen display (e.g., viainterface 86 that couples to row electrodes and another interface 86that couples to column electrodes). Note that the number of lines thatcoupled the one or more processing modules 42 to the respective one ormore DSCs 28, and from the one or more DSCs 28 to the respectiveinterfaces 86 may be varied (e.g., such as may be described by n and m,which are positive integers greater than or equal to 1). Note that therespective values may be the same or different within differentrespective embodiments and/or examples herein. Also, in other diagrams,the DSCs 28 are shown as interfacing with electrodes that are implantedwithin a bodily portion of the subject or implemented in a non-invasivemanner such that electrodes are in close proximity or in contact withthe surface of a bodily portion of the subject. In even other diagrams,the DSCs 28 are shown as interfacing with electrodes that coupled to oneor more sensing and/or stimulation points within the sheath that isoperative to facilitate sensing and/or stimulation to a bodily portionof the subject. Note that such a sensing and/or stimulation signalprovided from a DSC 28 may be tuned to have any desired electricalcharacteristics (e.g., amplitude, phase, frequency, wave shape, etc.).For example, consider an electrical stimulation implementation, theelectrical signaling provided from the DSC 28 may be tuned to providefor optimal effect and performance when interacting with a bodilyportion of the subject.

Note that the same and/or different respective signals may be drivensimultaneously sensed by the respective one or more DSCs 28 that coupleto electrodes 1410 within any of the various embodiments and/or examplesherein. In some examples, a common signal (e.g., having common one ormore characteristics) is implemented in accordance with self signaling,and different respective signals (e.g., different respective signalshaving one or more different characteristics) are implemented inaccordance with mutual signaling as described below. Again, as mentionedabove, note that the different respective signals that are driven andsimultaneously sensed via the electrodes 1410 may be differentiated fromone another.

FIG. 16A is a schematic block diagram of another embodiment 1601 of aDSC configured simultaneously to drive and sense a drive signal to anelectrode 1410 in accordance with the present invention. In thisdiagram, one or more processing modules 42 is configured to communicatewith and interact with a drive-sense circuit (DSC) 28-16 a. The one ormore processing modules 42 is coupled to a DSC 28-16 a and is operableto provide control to and support communication with the DSC 28-16 a.Note that the one or more processing modules 42 may include integratedmemory and/or be coupled to other memory. At least some of the memorystores operational instructions to be executed by the one or moreprocessing modules 42. In addition, note that the one or more processingmodules 42 may interface with one or more other devices, components,elements, etc. via one or more communication links, networks,communication pathways, channels, etc.

In this diagram, the one or more processing module 42 is configured toprovide a reference signal to one of the inputs of a comparator 1615.Note that the drive signal provided to the electrode 1410 is implementedto track, follow, match, etc. the reference signal provided to the oneof the inputs of the comparator 1615. As the drive signal provided tothe electrode 1410 may be affected based on one or more electricalcharacteristics of the electrode 1410 including any change thereof, theDSC 28-16 a is configured to adapt the drive signal to track, follow,match, etc. the reference signal. Note that the comparator 1615 mayalternatively be implemented as an operational amplifier in certainembodiments. The other input of the comparator 1615 is coupled toprovide a drive signal directly from the DSC 28-16 a to the electrode1410. The DSC 28-16 a is configured to provide the drive signal to theelectrode 1410 and also simultaneously to sense the drive signal and todetect any effect on the drive signal including any change of the drivesignal based on one or more electrical characteristics of the electrode1410.

The output of the comparator 1615 is provided to an analog to digitalconverter (ADC) 1660 that is configured to generate a digital signalthat is representative of the effect on the drive signal that isprovided to the electrode 1410. In addition, the digital signal isoutput from the ADC 1660 is fed back via a digital to analog converter(DAC) 1662 to generate the drive signal is provided to the electrode1410. In addition, the digital signal that is representative of theeffect on the drive signal is also provided to the one or moreprocessing modules 42. The one or more processing modules 42 isconfigured to provide control to and be in communication with the DSC28-16 a including to adapt the drive signal is provided to thecomparator 1615 therein as desired to direct and control operation ofthe electrode 1410 via the drive signal.

FIG. 16B is a schematic block diagram of another embodiment 1602 of aDSC configured simultaneously to drive and sense a drive signal to anelectrode 1410 in accordance with the present invention. In thisdiagram, one or more processing modules 42 is configured to communicatewith and interact with a drive-sense circuit (DSC) 28-16 b. The one ormore processing modules 42 is coupled to a DSC 28-16 b and is operableto provide control to and support communication with the DSC 28-16 b.Note that the one or more processing modules 42 may include integratedmemory and/or be coupled to other memory. At least some of the memorystores operational instructions to be executed by the one or moreprocessing modules 42. In addition, note that the one or more processingmodules 42 may interface with one or more other devices, components,elements, etc. via one or more communication links, networks,communication pathways, channels, etc.

This diagram has some similarities to the previous diagram with at leastone difference being that this diagram excludes the DAC 1662 of theprior diagram. In this diagram, within the DSC 28-16 b the analog outputsignal from the comparator 1615 is fed back directly to the input of thecomparator 1615 that is also coupled to the electrode 1410 therebyproviding the drive signal (and simultaneously sensing the drive signal)that is provided to the electrode 1410.

FIG. 17 is a schematic block diagram of an embodiment of circuitry thatis operative in accordance with one or more pacemaker and/or sensingleads associated with a subject 1701 and also includes a pictorialrepresentation 1702 of portions of the heart of the subject inaccordance with the present invention. On the left-hand side of thediagram, a subject 1701 is shown as being associated with circuitry 1710and one or more pacemaker and/or sensing leads. In certain examples,circuitry 1710 includes one or more processing modules 42 that are incommunication with one or more DSCs 28 that service the one or morepacemaker and/or sensing leads. In some implementations, the circuitry1710 is implanted inside the body of the subject. In otherimplementations, the circuitry 1710 is included mounted on the subjectin a noninvasive manner such that the circuitry 1710 may be readilyaccessed for maintenance, adjustment, configuration, etc. Even withinimplementations in which the circuitry 1710 is implanted inside the bodyof the subject, wireless communication means including our radiofrequency (RF), near-field communication (NFC), etc. may be used tofacilitate communication with the circuitry 1710 from one or more otherdevices that are externally located to the body of the subject.

On the right-hand side of the diagram, a pictorial representation 1702of portions of the heart of the subject is shown. With respect to theblood flow within the heart, oxygen-poor blood is received from the bodyvia the superior vena cava, the blood then travels to the rightventricle and subsequently via the pulmonary artery to the lungs wherethe oxygen-poor blood is oxygen enriched thereby generating oxygen-richblood. This oxygen-rich blood is subsequently received via the leftatrium from the lungs and enters the left ventricle after which it isreturned to the body via the aorta artery. In addition, there arevarious portions of the heart that include conductive cells that arecapable of carrying electrical signals including electrical impulsesfrom one portion of the heart to another.

In addition, with respect to these conductive cells within the hearts,they will undergo both depolarization and repolarization in accordancewith facilitating beating of the heart. Generally speaking, to primarychemicals provide the electrical charges within the hearts, namely,sodium (Na+) and potassium (K+). Considering a conductive cell, whenthat cell is resting, the majority of the potassium is on the inside ofthe conductive cell and the majority of the sodium is on the outside ofthe cell. Because of this to take their distribution, the conductivecell is negatively charged or may be viewed as a negative or polarizedconductive cell at rest. However, when the conductive cell becomesdepolarized, the interior of the conductive cell gains a net positivecharge thereby causing the conductive cell to contract. Depolarizationis the opposite operation of polarization in which the potassium movesout of the center of the conductive cell and sodium moves across thecell membrane thereby replacing the potassium within the cell gains thenet positive charge thereby causing the conductive cell to contract.

During depolarization process, an electrical wave travels through themyocardium of the conductive cells, and the response of the conductivecells within the hearts to this electrical wave causes them to gain thenet positive charge thereby causing the conductive cells to contract. Toprepare for a subsequent depolarization process, these conductive cellsundergo repolarization to return back to the electrical charges of theiroriginal state. In order for the conductive cells to perform thedepolarization process whereby they gain the net positive charge therebycausing the conductive cells to contract, those conductive cells mustundergo a repolarization so that the process may be performed for thenext heartbeat. Generally speaking, this process of positive charging ofthe conductive cells in accordance with depolarization, thereby causingthe appropriate portions of the heart to contract in the appropriatetimely manner, and the subsequent return of those conductive cells totheir original state in accordance with repolarization may be viewed asthe depolarization-repolarization process.

Within the heart, these conductive cells are arranged in a system ofelectrical pathways called the cardiac conduction system (e.g., theconduction system of the heart). The proper generation, timing, anddelivery of electrical impulses between different respective portions ofthe heart within this cardiac conduction system facilitate the beatingof the heart. As can be seen within the pictorial representation 1702 ofportions of the heart of the subject, the cardiac conduction systemincludes a sinoatrial (SA) node (alternatively referred to as the sinusnode), an atrioventricular (AV) node, the bundle of His (alternativelyreferred to as the His bundle or the common bundle), right and leftbundle branches, and Purkinje fibers. Note that the AV node and the Hisbundle are often referred to as the AV junction. In addition, note thatthe Purkinje fibers penetrate into the muscle mass of the left and rightventricles, approximately ¼ to ⅓ the way into the muscle mass of theleft and right ventricles.

In an example of operation of a heartbeat of the subject 1701,oxygen-poor blood is received by the heart from the body and undergoescertain processes to enrich the oxygen-poor blood thereby producingoxygen-rich blood which is then delivered to the body. When performingthis operation, the heart may be viewed as being an electrical andmechanical system such that the electrical and mechanical componentsthereof operate cooperatively. That is to say, there are two distinctcomponents of this process to facilitate the contraction, oxygenenriching, and pumping of the oxygen-rich blood out from the heart andback to the body. The heart operates in cooperation with the lungs thatperform the oxygen enrichment of the oxygen-poor blood that is receivedfrom the body thereby generating the oxygen-rich blood that is providedback to the body. In accordance with this operation, electrical impulsesare provided to particular portions of the heart, and that particularportion of the heart responds to that electrical impulse therebyproviding a mechanical response based on the electrical impulse. Themuscles of the heart respond mechanically by beating or contracting inresponse to such electrical stimulation provided by such electricalimpulses. When such mechanical beating or contraction occurs within theheart, the heart of the subject 1701 will generate both a heart rate anda blood pressure based on such response.

These electrical impulses provided via the respective and properpathways within the heart cause the heart to beat through process oftendescribed as automaticity. Within the body, when operating based on suchautomaticity, these specialized cells that have conductive capabilities,transmit and/or receive electrical impulses, such as the generation anddischarge of electrical current between different respective portions ofthe heart. In a healthy subject 1701, such electrical impulses aregenerated by the body and transmitted and received through the differentportions of the heart to facilitate the beating of the heart.

Specifically, within a healthy subject 1701, in accordance with theappropriate timing of different respective electrical impulses that areprovided via conductive cells of the heart, the heart facilitates theoperation of receiving oxygen-poor blood from the body via the superiorvena cave. This auction-poor blood enters the right atrium, which is theupper right chamber of the heart. The SA node is a group of specializedconductive cells of the heart that are located in the posterior wall ofthe right atrium near the superior vena cava via which the oxygen-poorblood is received from the body. The SA node operates as the naturalpacemaker of the cardiac system and generates and transmits anelectrical impulse that triggers atrial depolarization and contraction.When the SA node generates and transmits this electrical impulse, a waveof the conductive cells begins to depolarize. This electricaldepolarization results in the mechanical contraction of certain portionsof the heart. For example, this electrical impulse from the SA node isprovided to both the right and left atria of the hearts. The impulsetravels through the atria via inter-nodal electrical pathways down tothe AV node. In a typical healthy subject 1701, the SA node typicallygenerates these electrical impulses and transmits them at a rate of60-100 beats per minute (bpm).

These electrical impulses that are generated and transmitted from the SAnode are received at the AV node and the AV junction. The AV node isanother group of specialized conductive cells of the heart that arelocated in the lower portion of the right atrium, above the base of thevalve between the right atrium and the right ventricle, which is thetricuspid valve. The AV node does not possess pacemaker capability as dothe conductive cells within the SA node. The AV node operates to receivean electrical impulse from the SA node and to delay them in order toallow the atria of the heart to contract thereby failing filling theventricles with blood. In addition, in response to the electricalimpulse provided from the SA node, the AV node operates to receive thatelectrical impulse and conduct it down to the right and left ventriclesof the heart via the AV junction and the His bundle.

As the electrical impulse is received in the His bundle from the AVnode, the electrical impulse enters into the His bundle that is locatedin the upper portion of the intra-ventricular septum. In addition, theHis bundle connects the AV node to the left and right bundle brancheswithin the cardiac conduction system. The His bundle operates to directthe electrical impulse down both the left and right bundle branches, andthe left and right bundle branches further divide the electrical impulseinto the Purkinje fibers of the left and right ventricles of the heart.In a typical healthy subject 1701, the AV node typically generates theseelectrical impulses and transmits them at a rate of 40-60 bpm.

Note that any problems or deficiencies with respect to the conductivityof the various conductive cells within the heart will result in abnormaloperation of the heart, health problems, potential heart attack, andpossibly loss of life. For example, ineffectual electrical conductivitybetween the His bundle in the left and right bundle branches may resultin dysrhythmia, which is often associated with congestive heart failureresulting from abnormality in the normal rhythm of the heart. Inaddition, note that any problems or ineffectual operation of the SA nodecan cause sinus dysrhythmia.

FIG. 18 is a schematic block diagram showing an example 1800 of atypical/normal electrocardiogram (ECG) (alternatively referred to as anEKG) in accordance with the present invention. Oftentimes the subjectvisiting a medical professional undergoes testing during a stress testsuch that the medical professional monitors the ECG of the subjectduring the stress test (e.g., such as the subject walking on thetreadmill, an inclined treadmill, stair master, etc. and/or some otherexercise equipment) to see how the subject is responding and how thecardiovascular system of the subject is working. As described above, theheart may be viewed as being an electrical and mechanical system suchthat the electrical and mechanical components thereof operatecooperatively. When there is a problem with one or both of theelectrical and mechanical components of the heart, this electrical andmechanical system may not operate properly. This diagram shows anexample of normal operation of the heart based on the associated ECG.For example, when there is abnormality, poor electrical conduction or noconduction, disruption of the one or more components of the cardiacconduction system, etc., then the result may be problems with respect tothe heart rate being too slow or too fast, or it may disrupt thefunction of the heart altogether thereby causing significant risk tohealth and/or loss of life. Note that even in a healthy subject,sometimes problems may arise with respect to the cardiac conductionsystem such that the electrical signals have difficulty propagatingthrough the portions of the heart. In addition, note that non-electricalrelated problems with the heart may result in causing problems withinthe cardiac conduction system thereby inhibiting the transmission ofelectrical impulses via the different respective portions of the heart.

On the left-hand side of this diagram, the ECG shows the electricalresponse of the heart, which may be recorded by placing electrodes onthe chest and/or back of the subject. Note that while an ECG may berecorded using prior art ECG technology, ECG stickers placed on asubject that our service using DSCs as described herein can providesignificantly improved resolution and accuracy of the electricalresponse of the heart compared to prior art ECG technology. Electricalresponse of the heart is shown as an electrical signal having a varyingvoltage as a function of time in response to these electrical signalsthat propagate through the various portions of the heart therebyproducing the mechanical response of the muscles of the heart and themovement of blood through the heart and lungs within the cardiovascularsystem.

In an ECG of a healthy subject, the respective portions of theelectrical response of the heart are often described with respect to aPQRSTU response to identify the different waves/areas/portions of theECG. As the electrical signal is provided from the SA node, a P wave isgenerated within the ECG. During the P wave, the electrical impulsesprovided from the SA node to the left and right atria via the Bachman'sbundle thereby causing the atria to contract to push the lead to theleft and right ventricles. Also, during this process, the atriadepolarize in accordance with this contraction.

Next is the QRS complex. This is representative of the process by whichthe electrical impulse is delayed within the AV node, and then spreadvia the His bundle and via the right and left bundle branches to thePurkinje fibers of the left and right ventricles. Also, during thisprocess, the ventricles depolarize in accordance with their contraction.

Next is the T wave and the U wave, and note that often the U wave isconsidered to be part of the T wave. During the T wave, the left andright ventricles repolarize such that the muscles of the left and rightventricles relax in preparation for the next impulse to be deliveredfrom the SA node to the AV node in accordance with the next heartbeat.In addition, during the U wave, the Purkinje fibers of the left andright ventricles of the heart undergo repolarization in preparation forthe next impulse to be delivered from the SA node to the AV node inaccordance with the next heartbeat.

With respect to these different electrical impulses that propagatethrough different respective portions of the heart in accordance withthe heart going through a heartbeat cycle, a DSC as described hereinservicing a pacemaker lead or a sensing lead is operative to detect suchelectrical impulses, including the electrical impulses provided from thesinoatrial (SA) node to the atria, the electrical impulses provided fromthe SA node to the atrioventricular (AV) node, the electrical impulsesthat subsequently spread from AV node via the His bundle and the rightand left bundle branches to the Purkinje fibers of the right and leftventricles. In addition, note that a DSC as described herein theservices a single pacemaker lead is operative both to deliver impulsesof the pace signal and to sense cardiac response via one singleconductor of a pacemaker lead. As such, a pacemaker lead, when servicedby a DSC as described herein, may include as few as one single conductorand be able to effectuate both delivery of the pacemaker signal as wellas sensing of cardiac response including any of the various electricalimpulses that propagate through the heart during a heartbeat cycle. Notethat certain constructed pacemaker leads have characteristics of aninductive load. As such, a pacemaker lead having such inductive loadtype characteristics, when serviced by a DSC as described herein, maydetect inductive reactants characteristics associated with the pacemakerlead. However, using a DSC as described herein allows for very pacemakerleads designed differently than those currently employed in the priorart. For example, new pacemaker leads may alternatively be designed thatdo not have such inductive load type characteristics and yet still beserviced and operative in cooperation with the DSC to provide a pacesignal including the electrical impulses thereof.

In an example of operation and implementation, a DSC as described hereinis configured to perform simultaneous delivery of the impulses of thepace signal and also to sense cardiac electrical activity of the cardiacconduction system of the subject. Note that this operation will beperformed via a singular pacemaker lead that is serviced by such a DSC.The cardiac electrical activity of a subject is often described as beingbased on myocardial signals. Whereas the prior art pacemaker circuitincludes a sensor technology that is separate and independent from thesignal generation and delivery system, a pacemaker lead serviced by aDSC as described herein includes capability to perform both delivery ofthe impulses of the pace signal and also to sense the cardiac electricalactivity of the cardiac conduction system of the subject via a singularpacemaker lead. Note that such an implementation of it pacemaker leadserviced by a DSC as described herein includes capability both todeliver impulses of the pace signal and also to sense cardiac electricalactivity via the same pacemaker lead providing a significant improvementover prior art pacemaker technology. For example, prior art pacemakertechnology often uses electrocardiogram (ECG) (alternatively referred toas an EKG) sensing capability to monitor cardiac electric activity as anentirely separate component of such a system. That is to say, prior artpacemaker technology, when performing sensing of cardiac electricactivity operate using different components, elements, or a pacemakerlead including multiple conductors or elements such that one of theconductors or elements is implemented to perform delivery of the pacesignal, and another of the conductors or elements is implemented tofacilitate sensing of cardiac electrical activity. A pacemaker system asdescribed herein such that pacemaker functionality and also cardiacelectrical activity sensing functionality may be provided to a subjectvia a pacemaker lead that is serviced by a DSC is much less intrusive toa subject then prior art techniques. For example, the form factor orsize of a pacemaker lead including multiple conductors or elements ismuch larger than a singular pacemaker lead serviced by a DSC asdescribed herein that is operative to provide both pacemakerfunctionality and also cardiac electrical activity sensingfunctionality.

In addition, note that while the signal levels shown in this diagram arewithin the typical range, such signal levels may vary from subject tosubject. Also, while examples of common ranges of pacing impulse signalsfor electrical capture are also described herein, such as with referenceto FIG. 22, note that different hearts of different subjects may requiredifferent amounts of energy to elicit depolarization and contraction ofthe heart in accordance with proper cardiac function. For example, thecurrent levels typically provided within such pacing impulse signals iswithin the range of milliamps (mA), note again that different parts ofdifferent subjects may require different amounts of energy to facilitateproper cardiac function. Examples of parameters that can affect theamount of energy required may include any of a number of the position ofthe pacemaker lead, how well it is in contact with viable myocardialtissue/conductive cells of the heart, any underlying or pre-existingcondition of the subject, any medications currently being administeredto the subject, etc.

In another example of operation and implementation, a DSC that servicesa pacemaker lead as described herein is configured to provide deliveryof the impulses of a pace signal and also to sense cardiac electricalactivity during the delivery of the impulses of the pace signal. Whereasprior art cardiac electrical activity sensing functionality that isimplemented based on prior art pacemaker technology suffers fromelectrical saturation during the delivery of the impulses of the pacesignal and is unable to perform sensing of cardiac electrical activityduring the delivery of the impulses of the pace signal, a DSC thatservices a pacemaker lead as described here and is configured to sensecardiac electrical activity during delivery of the impulses of the pacesignal while delivering the impulses of the pace signal. This providessignificant improvement over prior art pacemaker technology that isunable to perform the detection of the cardiac electrical activityduring that particular time of delivery of an impulse of the pacesignal. This cardiac electrical activity sensing functionality, duringthe delivery of an electrical impulse of the pace signal, that isenabled using a DSC that services a pacemaker lead is described hereinprovides additional information to medical professionals to understandand diagnose cardiac operation of the subject that is not availableusing prior art cardiac electrical activity sensing functionality thatis implemented based on prior art pacemaker technology.

In yet another example of operation and implementation, operationaladaptation of a DSC that services a pacemaker lead as described hereinmay be performed based on continuous monitoring of cardiac electricalactivity of the subject including during delivery of the electricalimpulses of the pace signal. For example, one or more processing modulesinto an indication with the DSC that services a pacemaker lead asdescribed herein is operative to adjust any one or more operationalparameters of the DSC that is providing electrical impulses of the pacesignal via the pacemaker lead based on information that is acquired viathe cardiac electrical activity sensing functionality that is enabled bysuch an implementation as described herein (e.g., DSC that services apacemaker lead). For example, the one or more processing modules isconfigured to facilitate adjustment of any one or more of the variouselectrical characteristics of the pace signal that is delivered from theDSC via the pacemaker lead including any one or more of voltage and/orcurrent magnitude of the electrical impulses of the pace signal, thepulse width of electrical impulses of the pace signal, the total amountof energy and/or current delivered via the electrical impulses of thepace signal, the frequency or rate of the electrical impulses of thepace signal, etc.

FIG. 19 is a schematic block diagram of another embodiment 1900 of a DSCconfigured simultaneously to drive and sense a drive signal to anelectrode in accordance with the present invention. As with many diagramherein, this diagram shows one or more processing modules 42 configuredto interact with a drive-sense circuit (DSC) 28. In this diagram andothers, note that the coupling or connection between one or moreprocessing modules 42 and the DSC 28 may be made using any number ofcommunication channels, pathways, etc. (e.g., generally n, where n is apositive integer greater than or equal to 1).

Examples of one or more signals that may be provided between the DSCs 28and the one or more processing modules 42 to the DSC may include any oneor more of a reference signal such as provided from the one or moreprocessing modules 42 to one or more of the DSCs 28 (e.g., referred toas Vref in certain diagrams), power input, communication signaling,interfacing, control signaling, digital information provided from theDSC 28 to the one or more processing modules 42, digital informationprovided from the one or more processing modules 42 to the DSC 28, etc.In some examples, the DSC 28 itself includes a signal generator whoseoperation is controlled by the one or more processing modules 42 such assetting one or more parameters of the reference signal to be generatedand used as a basis to generate the drive signal. In addition, note thatthe one or more processing modules 42 may interface with one or moreother devices, components, elements, etc. via one or more communicationlinks, networks, communication pathways, channels, etc. that may beimplemented in any of a number of ways including wired communicationmedia, wireless communication media, optical communication media, and/orany other type of communication media.

The DSC 28 is implemented to generate a drive signal based on areference signal into provided via a single line via an electrode 1410to facilitate sensing and/or stimulation to a bodily portion of asubject. In one example, the electrode 1410 is implemented as apacemaker lead to facilitate the delivery of a pacing signal to a bodilyportion of the subject, such as to a particular location within theheart (e.g., in accordance with atrial and/or ventricle pacing of theheart of the subject). In another example, the electrode 1410 isimplemented as a sensing lead that is operative to detect one or moreelectrical signals that are transmitted through conductive cells of thesubject (e.g., such as the electrical signals transmitted via respectiveportions of the heart in accordance with a heartbeat cycle of thesubject). In yet another example, the electrode 1410 is implemented as asensing lead is operable to detect impedance of a bodily portion of thesubject (e.g., such as impedance of the heart of the subject, aparticular of the subjects such as the chest or thorax, and/or otherbodily portion of the subject etc.). In yet another example, theelectrode 1410 is implemented as connection between the DSC and a pointwith any sheath that may be in contact with or wrapped around a bodilyportion of the subject. In some implementations, the sheath includesmultiple points that are in contact with or wraparound a portion of thesubject to facilitate sensing and/or stimulation based on the particulararrangement and location of those points.

Note that the electrode 1410 may be implemented in a variety of wayswith respect to a subject. In one implementation, the electrode isimplanted within the subject. For example, in accordance with theelectrode 1410 operating as a pacemaker lead, the pacemaker lead isimplanted within the body of the subject and particularly placed at adesired location, typically within a particular portion of the heart soas to facilitate proper function of the heart of the subject based onthe appropriate delivery of a pacing signal. In one example, animplantable electrode 1410 that is implemented to facilitate atrialpacing is implanted into or near the sinoatrial (SA) node of the heartof the subject. In another example, an implantable electrode 1410 thatis implemented to facilitate ventricle pacing is implanted into or nearthe atrioventricular (AV) node of the heart of the subject. Anythingother examples, and implantable electrode 1410 that is implemented tofacilitate pacing is implanted into or near the atrium (e.g., the rightatrium) or a ventricle (e.g., the left or right ventricle) of the heartof the subject.

In another implementation, the electrode is associated with the subjectin a non-invasive manner. For example, in accordance with the electrode1410 operating as a non-invasive pacemaker lead, the pacemaker lead isexternal to the body of the subject, yet in contact with or associatedwith the subject at a location associated with the bodily portion, orwithin sufficient proximity to the subject at a location associated withthe bodily portion, such as on the surface of the skin of the subject,that will facilitate delivery of a pacing signal through the surface ofthe skin of the subject to the appropriate portion of the heart so as tofacilitate proper function of the heart of the subject based on theappropriate delivery of a pacing signal. In another example, inaccordance with the electrode 1410 operating to facilitate sensing of anelectrocardiogram (ECG) (alternatively referred to as an EKG) of thesubject, the electrode 1410 couples the DSC 28 is coupled via theelectrode 1410 to an ECG sticker that is in contact with surface of theskin of the subject at a location associated with the bodily portion(e.g., chest, the thorax, near the heart of the subject, etc.).

In addition, with respect to different implementations of the electrode1410 that are tailored to facilitate sensing and/or stimulation, notethat the electrode 1410 may be implanted within the subject ornon-invasive with respect to the subject such that the electrode 1410 isassociated with or in contact with the surface of a bodily portion ofthe subject.

Note that this implementation of a DSC 28 that is configured to drive asignal and simultaneously sense that signal including any effect,change, modification, etc. of that signal may be implemented to performdifferent functions in different implementations. Examples of differenttypes of signals that may be provided from the DSC 28 via the electrode28 include one or more of a sense signal, a pace signal, a currentsource signal, a current sink signal, a combination current source/sinksignal, a stimulation signal, etc. note that this configuration of oneor more processing modules 42 in communication with a DSC 28 thatservices and electrode 1410 may be configured to operate differently fordifferent purposes as may be desired in different applications.

Note that such an embodiment including a DSC 28 that services andelectrode 1410 that is in proximity to or in contact with the bodilyportion of the subject may be used for any a variety of purposesincluding delivery of a pace signal, nerve stimulator, musclestimulator, impedance sensor, etc. Also, only sensing, only stimulation,or both sensing and stimulation may be performed via a single electrode1410 that is serviced by a DSC 28. Such an implementation provides theability to perform the dual functionality of both sensing andstimulation via a single electrode 1410 having a very small form factor,size, etc. In addition, the reference signal that is employed by the DSC28 may any desired type and form (e.g., DC signal, square wave signal,triangle wave signal, sawtooth signal, etc., as just some examples oftypes and waveforms of signals, etc.). Generally speaking, any of thevarious aspects, embodiments, and/or examples of the invention (and/ortheir equivalents) (e.g., including one or more DSCs that service one ormore elements such as electrodes, pacemaker leads, conductive pointssuch as in a sheath, etc.) may be implementation to perform any one ormore variety of operations including delivery of a pace signal, nervestimulation, muscle stimulation, sensing of various electricalcharacteristics including voltage, current, and/or impedance, etc.

FIG. 20 is a schematic block diagram of an embodiment 2000 of multipleDSCs configured simultaneously to drive and sense drive signals toelectrodes, respectively, in accordance with the present invention. Thisdiagram has similarity to the prior diagram yet includes multiple DSCs28 that service respective electrodes 1410 may be associated withdifferent respective bodily portions. For example, a first DSC 28 iscoupled via an electrode 1410 to a first bodily portion, and one or moreadditional DSCs are coupled via respective electrodes 1410 to otherbodily portions, as shown by a DSC 28 that is coupled via an electrode1410 to an nth bodily portion. Generally speaking, any desired number ofrespective DSCs maybe implemented to service any desired number ofelectrodes 1410 that are associated with different respective bodilyportions.

Note that such a multiple DSC 28 and electrode 1410 implementation maybe implemented using any number of different types of electrodes 1410for different purposes. Examples of such different respective purposesmay be associated with providing pace making to a subject, stimulationto one or more bodily portions of the subject, sensing of one or moreelectrical characteristics such as electrical signals via conductivecells, impedance, etc. of the subject. Examples of different types ofsignals that may be delivered by the different respective DSCs 28include any one or more of delivery of a sense signal, a pace signal, acurrent source signal, a current sink signal, a stimulation signal,and/or any other type of signal. Note also that such a multiple DSC 28and electrode 1410 implementation may include any combination of one ormore implantable electrodes 1410 and/or non-invasive electrodes 1410.

In an example of operation and implementation, a first electrode 1410 isimplanted within the subject to facilitate delivery of a pace signal. Asecond electrode 1410 is placed within contact of or within sufficientproximity of the surface of the skin of the subject to facilitatestimulation of a bodily portion of the subject be a delivery of acurrent and/or voltage signal. A third electrode 1410 is implantedwithin the subject to facilitate measurement of impedance of aparticular bodily portion of the subject, such as the heart, the chestor thorax, etc. A fourth electrode 1410 is implemented within a sheaththat is in contact with or wrapped around a bodily portion of thesubject to facilitate sensing and/or stimulation of that lovely portionof the subject. Generally speaking, any desired implementation ofdifferent DSCs 28 and respective electrodes 1410 associated with thosedifferent DSCs, such as on a one-to-one basis such that each DSC 28services a respective electrode 1410, may be made to serve differentrespective purposes.

FIGS. 21A, 21B, and 21C are schematic block diagrams of embodiments2101, 2102, and 2103 of different types of pacemakers operable to beserviced by one or more DSCs in accordance with the present invention.There are a variety of different ways in which pace making functionalitymay be provided to a subject. In some examples, circuitry 1710 isimplanted within the subject, and the circuitry 1710 includes variouscomponents that may include one or more of one or more processingmodules 42, one or more DSCs 28, one or more energy or power sourcessuch as a battery or other storage device, and/or any other componentsor elements as desired or needed to facilitate various functionsincluding delivery of a pace signal including pulse generation tofacilitate the pacing, sensing, and/or any other operations that may beprovided to the subject. These diagrams showing certain portions of theheart of the subject may be understood also with reference to FIG. 17that provides more description of the heart.

Referring to embodiment 2101 of FIG. 21A, this diagram shows a singlechamber pacemaker that includes a single pacemaker leads that isprovided to a chamber of the heart (e.g., upper or lower chamber) of thesubject. This diagram shows an atrial pacemaker lead coupled fromcircuitry 1710 that is implanted in or near the sinoatrial (SA) node ofthe heart of the subject. This diagram shows a single chamber pacemakerincluding a single pacemaker lead. Note that certain implementations ofa single chamber pacemaker typically carries electrical impulses to theright ventricle of the heart of the subject. However, a single chamberpacemaker may be alternatively implemented to carry electrical impulsesto the sinoatrial (SA) node. This diagram shows a single chamberpacemaker that carries electrical impulses to the SA node.

In an example of operation and implementation, circuitry 1710 isimplanted within the body of the subject, and the atrial pacemaker lead(e.g., which may be implemented as an electrode 1410) passes via thesuperior vena cava of the heart of the subject and is implanted in ornear the sinoatrial (SA) node of the heart of the subject. The atrialpacemaker lead delivers a pace signal (e.g., composed of timelydelivered electrical impulses) to initiate the SA node that provides anelectrical impulse from the SA node to the left and right atria via theBachman's bundle causing the atria to contract to push the lead to theleft and right ventricles and also results in the depolarization of theatria, which generates the corresponding P wave that may be seen whenviewing and electrocardiogram (ECG) (alternatively referred to as anEKG) of the subject.

Again, an alternative implementations, a pacemaker lead delivers a pacesignal (e.g., composed of timely delivered electrical impulses) to theright ventricle of the heart of the subject to initiate theatrioventricular (AV) node of the heart of the subject and thecorresponding QRS complex associated with the electrical signals beingspread via the His bundle of the heart (alternatively referred to as thecommon bundle) and via the right and left bundle branches to thePurkinje fibers of the left and right ventricles of the heart that alsoresults and depolarization of the ventricles.

Referring to embodiment 2102 of FIG. 21B, this diagram shows a dualchamber pacemaker that includes two pacemaker leads that are providedrespectively to an upper and a lower chamber of the heart of thesubject. In an example of operation and implementation, an atrialpacemaker lead coupled from circuitry 1710 that is implanted in or nearthe sinoatrial (SA) node of the heart of the subject and also shows aright ventricular lead coupled from circuitry 1710 that implanted in ornear the right ventricle of the heart of the subject. This type ofpacemaker carries electrical impulses to the right ventricle and also tothe right atrium of the heart of the subject and provides the ability tocontrol the relative timing between the respective contractions of thevarious chambers of the heart of the subject during a heartbeat. Forexample, this implementation that includes a dual chamber pacemakerprovides the ability to control with high precision the initiation ofthe SA node and also the initiation of the AV node. For example, withincertain patients, even though the SA node may be initiated effectively,the electrical signaling via the conductive cells of the heart may beinsufficient to initiate the AV node and subsequent electrical signalingvia the conductive cells of the heart including the His bundle, theright and left bundle branches to the Purkinje fibers, etc.

Referring to embodiment 2103 of FIG. 21C, this diagram shows abiventricular pacemaker that includes three pacemaker leads that areprovided respectively to an upper chamber of both lower chambers of theheart of the subject. In an example of operation and implementation, anatrial pacemaker lead coupled from circuitry 1710 that is implanted inor near the sinoatrial (SA) node of the heart of the subject, a rightventricular lead coupled from circuitry 1710 that implanted in or nearthe right ventricle of the heart of the subject, and a left ventricularlead coupled from circuitry 1710 that implanted in or near the leftventricle of the heart of the subject. Biventricular pacing is sometimesalternatively referred to as cardiac resynchronization therapy. Oftentimes, this type of pace making is provided to a subject having verysevere heart problems including heart failure and/or abnormal electricalsystem operation of the various conductive cells within the heart. Thistype of pace making provides the ability to control with high precisionthe initiation of the SA node (via the electrical impulses provided viathe atrial pacemaker lead), the initiation of the AV node (via theelectrical impulses delivered via the right ventricle lead), and alsothe initiation of the repolarization of the left and right ventriclesincluding the relaxation of the muscles of the left and right ventriclesbefore the next electrical impulse is received by the SA node (via theelectrical impulses delivered via the left ventricle lead). In addition,the electrical impulses delivered via the left ventricle lead operate toimprove the repolarization of the Purkinje fibers of the left and rightventricles of the heart before the next electrical impulse is receivedby the SA node.

Note that different respective subjects within different degrees ofcardiovascular health may be treated differently using differentimplementations of pace making. This disclosure describes many differentimplementations by which pace making may be implemented using one ormore processing modules 42 and one or more DSCs 28 to providesignificantly improved control of signal level, timing, precision,sensing, etc. over existing pacemaker technology. For example, given thecomplete control of a reference signal is used within a DSC 28 that isconfigured to generate a pacing signal to be provided to one or moreportions of the heart of the subject, a pacing signal having any desiredsignal level, pulse duration, energy content, current level, voltagelevel, etc. may be delivered with very high precision and accuracy overexisting pacemaker technology.

FIG. 21D is a schematic block diagram of an embodiment of a method 2104for execution by one or more devices in accordance with the presentinvention. From certain perspectives, the method 2104 may be viewed asbeing a method for execution by a pacemaker system. The method 2104operates in step 2110 by operating a drive-sense circuit (DSC), operablycoupled to a pacemaker lead implemented with one single conductor, toreceive a reference signal and to generate a pace signal includingelectrical impulses based on the reference signal. In certain variantsof the method 2104, as shown in block 2112, the pacemaker lead isimplanted in or in proximity to a sinoatrial (SA) node or a ventricle ofa cardiovascular system of a subject. In certain other variants of themethod 2104, as shown in block 2114, the pacemaker lead is implanted inor in proximity to a ventricle of a cardiovascular system of a subject.

The method 2104 operates in step 2120 by operating the DSC to providethe pace signal from the DSC via the pacemaker lead to an electricallyresponsive portion of a cardiac conductive system of the subject tofacilitate cardiac operation of the cardiovascular system of thesubject. Note that muscles of a heart of the subject produce amechanical response to the electrical impulses of the pace signal tomove blood through the cardiovascular system of the subject.

The method 2104 operates in step 2130 by operating the DSC to sense, viathe pacemaker lead, cardiac electrical activity of the cardiovascularsystem of the subject that is generated in response to the pace signaland electrically coupled into the pacemaker lead. The method 2104operates in step 2140 by generating a digital signal that isrepresentative of the cardiac electrical activity of the cardiovascularsystem of the subject that is sensed via the pacemaker lead. Inaddition, the method 2104 operates in step 2150 by processing thedigital signal generated by the DSC to determine the cardiac electricalactivity of the cardiovascular system of the subject that is sensed viathe pacemaker lead.

Certain other variants of the method 2104 operate by adjusting one ormore electrical characteristics of the reference signal to facilitategeneration of the pace signal by the DSC to facilitate capture by thecardiac conductive system of the subject in response to the pace signal.Note that adjustment of the one or more electrical characteristics ofthe reference signal causes adjustment of at least one electricalcharacteristic of the pace signal including at least one of a magnitudeof the electrical impulses of the pace signal, a pulse width of theelectrical impulses of the pace signal, an amount of current leveldelivered via the electrical impulses of the pace signal, and/or afrequency or rate of the electrical impulses of the pace signal.

Certain other variants of the method 2104 operate by processing thedigital signal generated by the DSC to determine the cardiac electricalactivity of the cardiovascular system of the subject that is sensed viathe pacemaker lead including to determine whether there is capture bythe cardiac conductive system of the subject in response to the pacesignal. Based on a determination that there is no capture by the cardiacconductive system of the subject, variants of the method 2104 adjustingone or more electrical characteristics of the reference signal tofacilitate generation of the pace signal by the DSC to facilitatecapture by the cardiac conductive system of the subject in response tothe pace signal.

Note that adjustment of the one or more electrical characteristics ofthe reference signal causes adjustment of at least one electricalcharacteristic of the pace signal including at least one of a magnitudeof the electrical impulses of the pace signal, a pulse width of theelectrical impulses of the pace signal, an amount of current leveldelivered via the electrical impulses of the pace signal, and/or afrequency or rate of the electrical impulses of the pace signal.

Note that the DSCs may be implemented in any of a variety of waysincluding as described herein in various examples, embodiments, etc. Inone example, a DSC is implemented to include a comparator configured toproduce an error signal based on comparison of the reference signal tothe pace signal. The reference signal is received at a first input ofthe comparator, and the pace signal is received at a second input of thecomparator. The DSC also includes a dependent current supply configuredto generate the pace signal based on the error signal and to provide thepace signal via a single line that couples to the pacemaker lead and thesecond input of the comparator. The DSC also includes an analog todigital converter (ADC) configured to process the error signal togenerate the digital signal that is representative of the cardiacelectrical activity of the cardiovascular system of the subject that issensed via the pacemaker lead. Some variants of the method 2104 operateby adjusting a programmable gain of the dependent current supply.Scaling the programmable gain of the dependent current supply providesfor scaling of the error signal.

In another example, a DSC is implemented to include a power sourcecircuit operably coupled via a single line to the pacemaker lead. Whenenabled, the power source circuit is configured to provide an analogsignal via the single line coupling to the pacemaker lead. The analogsignal includes at least one of a DC (direct current) component or anoscillating component. The DSC also includes a power source changedetection circuit operably coupled to the power source circuit. Whenenabled, the power source change detection circuit is configured todetect an effect on the analog signal that is based on at least one ofan electrical characteristic of the pacemaker lead or the cardiacelectrical activity of the cardiovascular system of the subject that issensed via the pacemaker lead and to generate the digital signal that isrepresentative of the cardiac electrical activity of the cardiovascularsystem of the subject that is sensed via the pacemaker lead.

In some specific examples, the power source circuit is implemented toinclude a power source to source at least one of a voltage or a currentvia the single line to the pacemaker lead. The power source changedetection circuit is implemented to include a power source referencecircuit configured to provide at least one of a voltage reference or acurrent reference and a comparator configured to compare the at leastone of the voltage and the current provided via the single line to thepacemaker lead to the at least one of the voltage reference and thecurrent reference to produce the analog signal.

FIG. 22 is schematic block diagram showing an example 2201 of atypical/normal electrocardiogram (ECG) (alternatively referred to as anEKG) showing typical locations of pacing signals and also includes apictorial representation 2202 of the relationship between pulse signalimpulse amplitude and pulse width duration that facilitate capture andthat fail to schematic block in accordance with the present invention.

Referring to the example 2201, this diagram shows, and locations ofpacing signals relative to new atypical/normal ECG. For example, whenperforming atrial pacing only, such as provided to the sinoatrial (SA)node via an atrial pacemaker lead/electrode, an electrical impulse isdelivered via the pacemaker lead/electrode which subsequently results inthe heart response of the P wave. When performing the ventricle pacingonly, such as provided to right ventricle, the pacer spike is typicallyfollowed by the QRS complex.

With respect to the electrical characteristics of signals employed inaccordance with pace making, the upper right of the diagram shows somecommon ranges of pacing impulse signals for electrical capture by theelements of the heart in accordance with proper operation of the heart.Capture may be viewed as the minimum electrical stimulus needed toinitiate the operation of the heart and the movement of the electricalimpulses via the cardiac conduction system that results in the properoperation of the heart. For example, when providing a pace signal thatis insufficient, such as in terms of voltage, pulse width, current,etc., then the heart will not capture the signal and will not execute aheartbeat cycle. Referring again to the upper right-hand portion of thediagram, some common characteristics of the pacing impulse signals thatcommonly result in electrical capture thereby causing the properoperation of the heart may include one or more of a voltage within avoltage threshold range of 0.5 to 2 V (volts), a pulse width within therange of 0.5 to 0.8 ms (milli-secs), a current level within the range of50 to 90 mA (milli-amps). In addition, such pacing impulse signals aretypically delivered at a rate of between 60 and 100 times per minute tofacilitate the heart rate of 60 to 100 bpm.

Referring to the pictorial representation 2202 on the right-hand side ofthe diagram, considering the pace signal impulse threshold in voltsalong the vertical axis and the pulse width duration in millisecondsalong the horizontal axis, there are combinations of the magnitude ofthe pace signal and the pulse width duration that will facilitateelectrical capture and other combinations that results in no electricalcapture. For example, to the right-hand side of the dark line, when themagnitude of the pace signal is to the right of the dark line and thepulse width duration is above the dark line, that combination ofmagnitude of the pace signal and pulse width duration will result inelectrical capture thereby causing the proper operation of the heart.When the magnitude of the pace signal is to the left of the dark line inthe pulse width duration is below the dark line, that particularcombination of magnitude of pace signal impulse and pulse width durationwill not result in electrical capture. Note that the particular linethat indicates the demarcation between electoral capture and noelectrical capture may be different for different subjects, butgenerally speaking, this trend such showing combination of the pacesignal impulse magnitude and the pulse width duration must be ofsufficient value to provide the minimum electrical stimulus needed tofacilitate electrical capture of the heart will exist.

As such, when operating a pacemaker to facilitate proper operation ofthe heart of the subject, adjustment and tuning of the variousparameters by which the pacemaker delivers the pacing signal is made toensure that electrical capture is achieved for a particular patient. Apacemaker implemented as described herein using circuitry that includesa DSC that services one or more pacemaker leads provides much improvedresolution and ability to adjust any such parameters of the pacingsignal, including any one or more of magnitude, pulse width, energylevel, current level, voltage level, signal shape, waveform shape,and/or any other desired parameter in a much improved manner incomparison to prior art pacemaker technology. For example, by using aDSC as described herein to service a pacemaker lead, the current levelthat may be delivered via the pacemaker lead may be varied between 0 Aup to 1s or 10s of A (or even higher levels, though most likely notneeded for pacemaker applications) with extremely fine resolution andaccuracy. Again, as described above, a current level within the range of50 to 90 mA is common for many pacemaker applications, and a DSC thatservices a pacemaker lead as described herein may be configured andimplemented to provide current levels within any desired range as neededwithin pacemaker applications to assist and facilitate proper cardiacfunction of the subject.

In one implementation, a DSC is configured to provide any such desiredcurrent level with very high resolution and accuracy (e.g., from 0 A toa few microamps to 1 amp or more). Such a DSC is also configured todetect and sense of electrical signals such as those associated withcardiac electrical activity of the subject with very high resolution andaccuracy (e.g., from 0 A to a few nanoamps to a few microamps to 1s or10s of amps or more). Note that the electrical signals associated withcardiac electrical activity of the subject are typically in a lowerrange than 1s or 10s of amps, and a DSC that services a pacemaker leadand also provides cardiac electrical activity sensing functionality asdescribed herein may be configured and implemented to detect and sensecardiac electrical activity of the subject within any desired range(e.g., from 0 A to a few nanoamps to a few microamps to a few milliampsor more, etc.).

In addition, by using a DSC is described and to service the pacemakerlead, the voltage level that may be delivered via the pacemaker lead maybe varied between zero holds up to 1s or 10s of volts (or even higherlevels, though most likely not needed for pacemaker applications) withextremely fine resolution and accuracy. In another implementation, DSCis configured to provide any desired voltage level with very highresolution and accuracy (e.g., from zero V to a few microvolts or a fewmillivolts to 5 V or 10 V). Also, by using a DSC is described and toservice the pacemaker lead, the pulse width of a pacing signal that maybe delivered via the pacemaker lead may be adjusted to any desired valuevaried between 0 seconds up to 1s or 10s of microsecs to 1s or 10s ofmilliseconds (or even longer pulse widths, though most likely not neededfor pacemaker applications) with extremely fine resolution and accuracy.

Given the total flexibility by which a reference signal may be generatedand used within a DSC as described herein when servicing a pacemakerlead (e.g., such as using signal generator or within one or moreprocessing modules), any of the parameters of the pacing signal may beadjusted to any desired value with extremely fine resolution andaccuracy in a manner much improved over prior art pacemaker technology.

FIGS. 23A and 23B are schematic block diagrams of examples of pacingsignals that may be used in accordance with the present invention.

Referring to example 2201 of FIG. 23A at the top of the diagram, thisshows one possible example of the pacing signal such that the respectiveelectrical impulses are delivered approximately once every second tofacilitate beating of the heart at 60 beats per minutes, such that thereis one cycle per second, corresponding to a pacing signal having afrequency of 1 Hz. While the voltage magnitude and pulse width of theelectrical impulses may vary in different applications as required fordifferent subjects, one example would include electrical impulses havinga voltage magnitude of approximately 1.75 V and pulse width ofapproximately 0.6 ms. Example 2302 of FIG. 23A at the bottom of thediagram shows such an example of an electrical impulse having a voltagemagnitude of approximately 1.75 V and pulse width of approximately 0.6ms in an enlarged view.

Referring to example 2203 of FIG. 23B at the top of the diagram, thisshows another possible example of the pacing signal such that therespective electrical impulses are delivered approximately once everysecond to facilitate beating of the heart at 60 beats per minutes, suchthat there is one cycle per second, corresponding to a pacing signalhaving a frequency of 1 Hz. While the current magnitude and pulse widthof the electrical impulses may vary in different applications asrequired for different subjects, one example would include electricalimpulses having a current magnitude of approximately 75 mA and pulsewidth of approximately 0.6 ms. Example 2304 of FIG. 23B at the bottom ofthe diagram shows such an example of an electrical impulse having acurrent magnitude of approximately 75 mA and pulse width ofapproximately 0.6 ms in an enlarged view.

In addition, note that while the electrical impulses described incertain of the previous diagram show square wave electrical impulses,note that alternative waveform shapes may be used as desired. Forexample, an electrical impulse that has a rising edge that reaches themaximum magnitude of the electrical impulse, and then reduces in valueor decays during the pulse width, before returning to zero mayalternatively be used. In one possible example, consider the top of theelectrical impulse shown in certain of the previous diagrams as notbeing flat, yet having a different shape during the duration of thepulse width, such as reducing in value from 1.7 V to 1.6 V during thepulse width or reducing in value from 75 mA to 65 mA during the pulsewidth. Generally speaking, the particular shape of the electricalimpulses may be made in accordance with any desired shape using a DSCthat is implemented to service a pacemaker lead is described herein.

Again, given the total flexibility by which a reference signal may begenerated and used within a DSC as described herein when servicing apacemaker lead (e.g., such as using signal generator for within one ormore processing modules), any of the parameters of the pacing signalincluding voltage level, current level, pulse width, frequency, shape,etc. may be adjusted to any desired value with extremely fine resolutionand accuracy in a manner much improved over prior art pacemakertechnology.

FIGS. 24A and 24B are schematic block diagrams of other embodiments 2401and 2402 of DSCs configured simultaneously to drive and sense drivesignals to electrodes, respectively, in accordance with the presentinvention.

Referring to embodiment 2401 of FIG. 24A, this diagram provides analternative implementation by which a DSC 28 may be implemented, asshown by DSC 28-24A. As with other embodiments, examples, etc. herein,one or more processing modules 42 is implemented to interact andcommunicate with the DSC 28-24A in this diagram. Note that the one ormore processing modules 42 of this diagram in any other diagram hereinmay also be in communication with one or more other devices includingother sensors. For example, one or more processing modules 42 is incommunication with one or more of a temperature sensor, accelerometer, athermometer, a humidity sensor, a barometer, and/or any other sensor inaddition to being in communication with a DSC such as DSC 28-24A in thisdiagram. Note that the one or more processing modules 42 and/or a DSCsuch as the DSC 28-24A of this diagram may be in communication with oneor more other devices via one or more wired communication links, one ormore wireless communication links such as using radiofrequency (RF)communication, near-field communication (NFC), inductive communicationlink, etc. Considering an implementation in which a device that includesthe one or more processing modules 42 and/or a DSC, such as the DSC28-24A of this diagram, are implanted within a subject, and considerthat those devices are powered by a rechargeable battery, note thatcharging of that battery may be performed using wireless charging suchas described in U.S. Utility patent application Ser. No. 16/428,063,entitled “Wireless Power Transfer and Communications,” filed May 31,2020, pending, and U.S. Utility patent application Ser. No. 16/428,063,entitled “Wireless Power Transfer with In-line Sensing and Control,”filed May 31, 2020.

The DSC 28-24A includes a signal generator 2410 that is configured toreceive a control signal from the one or more processing modules 42 thatspecifies one or more parameters of the reference signal. Examples ofone or more parameters of the reference signal may include any one ormore of amplitude/magnitude, pulse width, frequency, type, waveform,phase, etc. Note that the reference signal may include more than onefrequency in certain implementations. For example, two or more signalsmay be included within the drive signal that is provided from the DSC28-24A to serve two or more respective functions such as delivery ofpace signal and sensing, among other possibilities. In addition, notethat the reference signal may be of any desired type and having anydesired waveform. For example, in some examples, the reference signal isa sinusoidal signal such as may be used in accordance with sensing. Notethat the reference signal may be any other type of signal including DCsignal, square wave signal, triangle wave signal, sawtooth signal, etc.,as just some examples of types and waveforms of signals. In accordancewith delivering a pacing signal to a subject, the reference signal maybe a square wave type signal that includes electrical impulses of aparticular magnitude, pulse width, energy level, current level, voltagelevel, and/or any other desired parameter such that the electricalimpulses are delivered at a particular desired frequency (e.g., 60-100times a minute such as in accordance with facilitating a regular andcontinuous heartbeat within the subject).

In addition, in this diagram as well as others that pictorially show asignal generator 2410, note that any alternative examples may excludesuch a signal generator 2410 within such as implementation of a DSC, andthe one or more processing modules 42 may be configured to provide thereference signal directly to the DSC. For example, the one or moreprocessing modules 42 may include functionality of such a signalgenerator 2410 therein and the functionality to generate a referencesignal having any such desired parameters.

The reference signal is provided to an input of a comparator 2415, whichmay alternatively be implemented as an operational amplifier. Anotherinput of the comparator 2415 receives the drive signal that is alsoprovided via a single-line to the electrode 1410 to a bodily portion ofthe subject. The drive signal is generated by a dependent current supplythat is powered by a power supply (e.g., Vdd) and that is controlledbased on an error signal, Ve, that is generated by the comparator 1415as it compares the drive signal to the reference signal. Note that theerror signal, Ve, at the output of the comparator 2415 is a signal isproportional to the current that is transmitted to or received from thebodily portion of the subject via the electrode 1410. In this diagram,the error signal, Ve, is passed through and analog to digital converter(ADC) 2460 to generate a digital signal that is representative of one ormore electrical characteristics of the drive signal including anychanges of the drive signal based on one or more electricalcharacteristics of the electrode 1410, one or more electrical signalscoupled into the electrode 1410 from the subject, and/or any otherchange to the drive signal.

The digital signal is provided to the one or more processing modules 42and also provided to a DAC 2462 to generate an analog control signalthat controls the amount of current that is output from the dependentcurrent supply via the single-line to the electrode 1410. Note that theamount of current, i, that is output from the dependent current supplybased on the error signal, Ve, is a function of a programmable scalefactor, k, of the dependent current supply such that: i=k×Ve. In certainexamples, note also that the one or more processing modules 42 isconfigured to adjust a programmable gain of the dependent currentsupply. Note that scaling the programmable gain of the dependent currentsupply provides for scaling of the error signal, Ve. Control of thecurrent, i, that is output from the dependent current supply may beeffectuated by appropriate control of the reference signal as well asthe programmable gain of the dependent current supply.

Consider an implementation of the DSC 28-24A servicing a pacemaker lead,such that the electrode 1410 includes a pacemaker lead. Note that theability to provide current signal of very high precision in terms of anyone or more magnitude, pulse width, energy level, current level, voltagelevel, and/or any other desired parameter in comparison to prior artpacemaker technology allows the pacemaker lead/electrode 1410 to beimplemented in a different and improved manner. For example, certainprior art pacemaker leads are implemented to have a very low impedance(e.g., 1s to 10s of Ohms or even lower impedance) along the length ofthe prior art pacemaker lead and are terminated with a very highimpedance termination (e.g., 400 to 1200 Ohms) to limit the amount ofcurrent that is delivered via the prior art pacemaker lead to preservebattery power.

For example, many prior art pacemaker systems include circuitry thatincludes a signal generator and a battery and that generates a signalhaving a constant voltage, and the higher the impedance of the prior artpacemaker lead, then the lower will be the current drain from thecircuitry. For example, the lead tip electrodes of certain prior artpacemaker leads are implemented to have relatively high resistance, suchas 400 to 1200 Ohms to minimize the current flow provided from thecircuitry via the prior art pacemaker lead and also to preserve controllong the life of the battery. In addition, many prior art pacemakerleads that are designed to facilitate sensing as well necessarilyrequire multiple respective electrodes with and the prior art pacemakerlead. For example, consider a prior art pacemaker lead that includesmultiple respective electrodes therein, such that a first electrodeimplemented there in is to facilitate delivery of the electricalimpulses of the pace signal, and a second electrode implemented then isto facilitate sensing of one or more electrical signals of the subject.

In an example of operation and implementation, a DSC 28 as describedherein (e.g., including DSC 28-24A) that services a pacemaker leadincluding as few as one single electrode is configured to facilitateboth delivery of the electrical impulses of the pace signal and also tofacilitate sensing of one or more electrical signals of the subject beat that one single electrode. Prior art pacemaker leads do not cannotprovide this functionality and require different respective electrodeswithin such a prior art pacemaker lead to perform different respectivefunctions. A DSC 28 as described herein (e.g., including DSC 28-24A)that services a pacemaker lead provides a significant improvement overprior art pacemaker leads such that the size of a pacemaker lead that isserviced by a DSC 28 as described herein may be implemented to have muchsmaller size and be less intrusive when implanted into the subject. Forexample, given that both delivery of the electrical impulses of a pacesignal and also sensing of one or more electrical signals of the subjectmay be made via one single electrode, the overall size of a pacemakerlead may be reduced significantly when implemented as described hereinin comparison to prior art pacemaker technology.

The precision and control provided by a DSC 28 as described herein(e.g., DSC 28-24A of this diagram) obviates the need for having a veryhigh impedance termination on a prior art pacemaker lead. In an exampleof operation and implementation, a DSC 28 as described here and theservice is a pacemaker lead is configured to deliver the current levelof any desired value thereby preserving the battery without requiring avery high up impedance termination as is often included on a prior artpacemaker lead. A DSC 28 as described that is configured to service apacemaker lead is operative to control the amount of current deliveredvia the pacemaker lead within the respective electrical impulses with ahigh degree of precision and accuracy thereby prolonging and extendingthe life of an energy source such as a battery implemented within such apacemaker application.

In addition, note that such a pacemaker lead that is serviced by a DSC28 as described herein (e.g., including DSC 28-24A of this diagram) isoperative to perform both delivery of the pace signal to a desiredportion of the heart of the subject and also to detect cardiacelectrical activity of the subject. As such, and implementationincluding one or more processing models 42 a DSC 28 that services apacemaker lead may be implemented to operate in a closed loop form suchthat detection of cardiac electrical activity of the subject is made andthat information employed by the one or more processing modules 42 toadjust operation of the pace signal delivered via the pacemaker leadfrom the DSC 28. This may be viewed as a closed loop implementation inwhich adaptation of the pace signal provided from the DSC 28 via thepacemaker lead is adapted based on detection of the cardiac electricalactivity of the subject that is made simultaneously and concurrentlyduring operation when delivering the pace signal.

Referring to embodiment 2402 of FIG. 24B, this diagram is similar to theprior diagram with at least one difference being that a DSC 28-24Bemploys an analog control signal that is provided directly based on theerror signal, Ve, that is generated from the comparator 2415 to controlthe amount of current that is output from the dependent current supplyvia the single-line. In certain examples, the dependent current supplyconnected to a positive power supply voltage, such as Vdd. Note thatthis diagram does not include or require the DAC 2462 as shown in theprior diagram. Note that there may be implementations in which theembodiment 2401 of FIG. 24A is preferred to the embodiment 2402 of FIG.24B. For example, there may be instances in which digital processing,such as filtering, scaling, etc. is desired to be performed on a digitalrepresentation of the error signal, Ve, that is generated by the ADC2460. In such an instance, that digital representation of the errorsignal, Ve, may undergo such additional processing within DAC 2462 (orin another component implemented between ADC 2460 and DAC 2462) beforeoutputting the analog control signal that controls the amount of currentthat is output from the dependent current supply via the single-line tothe electrode 1410.

In addition, with respect to this diagram and others described hereinthat include an electrode 1410 that is in proximity to or in contactwith a bodily portion of the subject, note that an additional electrode1410 may be implemented to provide a return electrical signal path tothe ground of a DSC 28 (e.g., such as to the ground connection of asignal generator 2410 within DSC 28-24A). In even other implementations,the body of the subject serves as the return path instead of using adedicated electrode 1410. This alternative variation of including anadditional electrode 1410 as a return path is also shown on thesubsequent diagram and may be included in any other implementation thatincludes an electrode implemented that is in proximity to or in contactwith a bodily portion of the subject for any of the many variety ofpurposes as described herein.

In an example of operation and implementation, a pacemaker systemincludes a drive-sense circuit (DSC) operably coupled to a pacemakerlead. The DSC is operably coupled and configured to receive a referencesignal and to generate a pace signal including electrical impulses basedon the reference signal. When enabled, the DSC configured to provide thepace signal via the pacemaker lead to an electrically responsive portionof a cardiac conductive system of a subject to facilitate cardiacoperation of a cardiovascular system of the subject. Muscles of a heartof the subject produce a mechanical response to the electrical impulsesof the pace signal to move blood through the cardiovascular system ofthe subject. The DSC is also configured to sense, via the pacemakerlead, cardiac electrical activity of the cardiovascular system of thesubject that is generated in response to the pace signal andelectrically coupled into the pacemaker lead. The DSC is also configuredto generate a digital signal that is representative of the cardiacelectrical activity of the cardiovascular system of the subject that issensed via the pacemaker lead.

The pacemaker system also includes one or more processing modules thatincludes and/or is coupled to memory. The memory that stores operationalinstructions. When enabled, the one or more processing modules isconfigured to execute the operational instructions to generate thereference signal and to process the digital signal generated by the DSCto determine the cardiac electrical activity of the cardiovascularsystem of the subject that is sensed via the pacemaker lead.

In certain examples, the pacemaker lead is implanted in proximity to orinto a sinoatrial (SA) node of the cardiovascular system of the subject.In other examples, the pacemaker lead is implanted in proximity to orinto a ventricle of the cardiovascular system of the subject. Also, notethat the pacemaker lead is implemented with one single conductor. Notethat both stimulation (e.g., providing of the impulses of the pacesignal) and sensing are performed by the DSC vis the same one singleconductor.

In certain other examples, when enabled, the one or more processingmodules is further configured to execute the operational instructions toadjust one or more electrical characteristics of the reference signal tofacilitate generation of the pace signal by the DSC to facilitatecapture by the cardiac conductive system of the subject in response tothe pace signal. Note that adjustment of the one or more electricalcharacteristics of the reference signal causes adjustment of at leastone electrical characteristic of the pace signal including at least oneof a magnitude of the electrical impulses of the pace signal, a pulsewidth of the electrical impulses of the pace signal, an amount ofcurrent level delivered via the electrical impulses of the pace signal,and/or a frequency or rate of the electrical impulses of the pacesignal.

When enabled, the one or more processing modules is further configuredto execute the operational instructions to process the digital signalgenerated by the DSC to determine the cardiac electrical activity of thecardiovascular system of the subject that is sensed via the pacemakerlead including to determine whether there is capture by the cardiacconductive system of the subject in response to the pace signal. Basedon a determination that there is no capture by the cardiac conductivesystem of the subject, the one or more processing modules is furtherconfigured to execute the operational instructions to adjust one or moreelectrical characteristics of the reference signal to facilitategeneration of the pace signal by the DSC to facilitate capture by thecardiac conductive system of the subject in response to the pace signal.Note that adjustment of the one or more electrical characteristics ofthe reference signal causes adjustment of at least one electricalcharacteristic of the pace signal including at least one of a magnitudeof the electrical impulses of the pace signal, a pulse width of theelectrical impulses of the pace signal, an amount of current leveldelivered via the electrical impulses of the pace signal, and/or afrequency or rate of the electrical impulses of the pace signal.

Note that the DSCs may be implemented in any of a variety of waysincluding as described herein in various examples, embodiments, etc. Incertain examples, the DSC includes a comparator configured to produce anerror signal based on comparison of the reference signal to the pacesignal. The reference signal is received at a first input of thecomparator, and the pace signal is received at a second input of thecomparator. The DSC also includes a dependent current supply configuredto generate the pace signal based on the error signal and to provide thepace signal via a single line that couples to the pacemaker lead and thesecond input of the comparator. The DSC also includes an analog todigital converter (ADC) configured to process the error signal togenerate the digital signal that is representative of the cardiacelectrical activity of the cardiovascular system of the subject that issensed via the pacemaker lead. When enabled, the one or more processingmodules is further configured to execute the operational instructions toadjust a programmable gain of the dependent current supply, whereinscaling the programmable gain of the dependent current supply providesfor scaling of the error signal.

In certain other examples, the DSC includes a power source circuitoperably coupled via a single line to the pacemaker lead. When enabled,the power source circuit is configured to provide an analog signal viathe single line coupling to the pacemaker lead, and wherein the analogsignal includes at least one of a DC (direct current) component or anoscillating component. The DSC also includes a power source changedetection circuit operably coupled to the power source circuit. Whenenabled, the power source change detection circuit is configured todetect an effect on the analog signal that is based on at least one ofan electrical characteristic of the pacemaker lead or the cardiacelectrical activity of the cardiovascular system of the subject that issensed via the pacemaker lead and to generate the digital signal that isrepresentative of the cardiac electrical activity of the cardiovascularsystem of the subject that is sensed via the pacemaker lead.

In some specific examples, the power source circuit is implemented toinclude a power source to source at least one of a voltage or a currentvia the single line to the pacemaker lead. The power source changedetection circuit is implemented to include a power source referencecircuit configured to provide at least one of a voltage reference or acurrent reference. The power source change detection circuit is alsoimplemented to include a comparator configured to compare the at leastone of the voltage and the current provided via the single line to thepacemaker lead to the at least one of the voltage reference and thecurrent reference to produce the analog signal.

FIGS. 25A and 25B are schematic block diagrams of examples orembodiments 2501 through 2506 of extra pathways within the heart of asubject that can cause tachycardias and one or more DSCs configuredsimultaneously to drive and sense drive signals to electrodes,respectively, capability to provide capability to reduce or eliminatetachycardias within the subject in accordance with the presentinvention.

With respect to the various electoral impulses that propagates through adaring apart the cycle, sometimes there are problems with the electricalpathways of the cardiac conduction system or the components of the heartthat generate the electrical impulses. In some instances, when there areproblems with the electrical pathways of the cardiac conduction system,the result may be an abnormally fast heartbeat, which is referred to astachycardias, or a slow heartbeat, which is referred to as bradycardias.With respect to bradycardias, the body's natural or normal pacemaker,the sinoatrial (SA) node, does not operate properly or with regularity.This may be referred to as sinus node dysfunction thereby causing aheartbeat that is too slow. A slow heartbeat and bradycardias may betreated by an appropriately implemented pacemaker, such as using a DSCserviced pacemaker lead as described herein.

With respect to tachycardias, or a fast heartbeat, this often occurswhen there is an extra electrical path in addition to the normal pathbetween the atrioventricular (AV) node and the His bundle. For example,the electrical impulse that is received in and delayed in the AV nodeand is being spread via the His bundle is also coupled via an extra oraccessory electric pathway back to the AV node. In a specific example,as the electrical impulse is transmitted from the AV node and is beingspread via the His bundle and subsequently to the right and left bundlebranches, a portion of that electrical impulse also makes its way viathe extra or accessory electric pathway back to the AV node. Such anextra or accessory electric pathway back to the AV node is sometimesreferred to as Wolf-Parkinson-White (WPW) syndrome. When such an extraor accessory electric pathway is included within the AV node, thecoupling of the electrical impulse back into the AV node is sometimesreferred to as AV node reentry or dual AV node pathways. Generallyspeaking, when there are extra or accessory electric pathways within thecardiac conduction system, as an electrical impulse is coupled via anormal path within the cardiac conduction system in accordance withfacilitating normal heart operation, the impulse may unfortunately alsobe coupled via an extra or accessory electrical pathway. This willresult in improper operation of the heart. In instance where electoralimpulse reenters the AV node, this can subsequently result in anabnormally fast heartbeat. Note that such extra or accessory electricpathways may unfortunately occur in various parts of the heart forvarious reasons, including congenital deficiencies in the formation ofthe heart during gestation of the subject, damage of the heart for anyof a variety of reasons including physical or electrical trauma, etc.Considering a specific example in which there is an extra or accessoryelectric pathway between the atria and the ventricles, this canunfortunately result in an electrical impulse making a continuous loopwithin the heart thereby producing an undesired fast heartbeat(tachycardias).

Referring to example 2501 of FIG. 25A on the left-hand side of thediagram, this diagram shows AV node reentry or dual AV node pathwayssuch that there is an extra pathway between the atria and ventricles,which is separate from or with in the AV node, and the electricalimpulses from the SA node that are supposed to be received in anddelayed in the AV node and is being spread via the His bundle is alsocoupled via an extra or accessory electric pathway back to the AV nodeare unfortunately caught in a continuous loop and reenter the AV nodethereby producing an abnormal electrical impulse that is received by theAV node and can result in an abnormally fast heartbeat. Each time theimpulse completes a circuit, including via this extra or accessoryelectric pathway back to the AV node, the heart beats. In extremesituations this can result in a very rapid heartbeat that is verydangerous for the subject.

In another specific example, instead of the heart including an extra oraccessory electric pathway within the cardiac conduction system, theremay be an abnormal “focus” within the heart (e.g., a group of conductivecells) that unfortunately acts as a second SA node or natural pacemakerin addition to the proper and primary SA node. When this abnormal“focus” within the heart unfortunately generates electrical impulsesitself, in addition to the electrical impulses generated by the properand primary SA node, this also may generate an abnormally fastheartbeat. Such an abnormal “focus” may be located in different portionsof the heart, such as in either the upper (atria) or lower chambers(ventricles).

Referring to example 2502 of FIG. 25A on the right-hand side of thediagram, this shows dual pathways within the AV node. For example, thetypical electrical pathway between the atrium to the His bundle via theAV node, there are unfortunately dual electric pathways. In manyinstances, one of them is faster than the other (e.g., one may havebetter electrical conductivity than the other and couples electricalimpulses more quickly than the other).

Referring to example 2503 of FIG. 25B, this diagram is shaped similar tothe example 2502 of FIG. 25A and also shows the electrical impulses as afunction of time, consider t1 being a first time, t2 being a second timeafter t1, and so on through t4. As can be seen, the electrical impulsesprovided from the atrium at a first time t1 and propagates via one ofthe duel pathways within the AV node during a second time t2.Unfortunately, during a third time t3, the electrical impulse is notonly coupled towards the His bundle but also via the dual electricpathway within the AV node via this continuous loop within the AV node.Then, during the fourth time t4 electrical impulse is coupled from theHis bundle towards the left and right bundle branch is and also backtowards the atrium.

Referring to example 2503 of FIG. 25B, as can be seen, there isincreased electrical signal level due to AV node reentry via the dual AVnode pathways within our hearts that unfortunately includes an extra oraccessory electric pathway back to the AV node. As can be seen, duringtimes t3 and t4, there is not only the normal electrical impulses thatare propagated through the cardiac conduction system, but also theadditional electrical impulses that are unfortunately coupled back tothe AV node.

A DSC serviced pacemaker lead or sensing lead is operative to detect theincreased electric signal level due to such an extra or accessoryelectric pathway (e.g., back to the AV node in this particularinstance). In addition, such a DSC serviced pacemaker lead or sensinglead is operative to detect the particular timing of such increasedsignal levels that may result from an extra or accessory electricpathway.

Referring to embodiment 2503 of FIG. 25B, this shows one possibleimplementation by which one or more processing modules 42 is incommunication with the DSC 28 that services electrode 1410. In thisimplementation, the electrode 1410 is implemented not only to facilitatesensing of cardiac activity by the DSC 28 but also to provide a currentsink signal that is provided from the DSC 28 to reduce or eliminate theextra electrical impulse that is unfortunately traveling via the extraor accessory electric pathway. This implementation includes a singleelectrode 1410 is operative to perform both sensing of the additionalelectric activity and also to provide a current sink signal to reduce oreliminate the extra electrical impulse to provide treatment of thetachycardia. By providing a current sink signal, such as a signal theone opposite to the extra electrical impulse that is traveling via theextra or accessory electric pathway, tachycardia within the subject maybe reduced or eliminated.

Referring to embodiment 2503 of FIG. 25B, this shows another possibleimplementation by which one or more processing modules 42 is incommunication with a first DSC 28 that services a first electrode 1410and also the second DSC 28 that services the second electrode 1410. Thefirst electrode 1410 is implemented to facilitate sensing of cardiacactivity by the first DSC 28. The second electrode 1410 is implementedto facilitate delivery of the current sink signal by the second DSC 28to reduce or eliminate the extra electrical impulse to provide treatmentof the tachycardia. In a similar location, two different electrodes 1410are implemented to perform two different purposes (e.g., the first oneto facilitate sensing and the second one to facilitate delivery of thecurrent sink signal).

Because a DSC 28 as described herein has the ability to perform sensingwith such high level of sensitivity, resolution, granularity, etc., anappropriately provided current sink signal to counter the electricalimpulse traveling via the extra or accessory electric pathway may bereduced or eliminated thereby reducing or eliminating the abnormallyfast heart beat associated with tachycardia.

FIGS. 26A and 26B are schematic block diagrams of other embodiments 2601and 2602 of DSCs configured simultaneously to drive and sense drivesignals to electrodes, respectively, and that include capability toprovide current sink signals in accordance with the present invention.

Referring to embodiment 2601 of FIG. 26A, this diagram is similar to theembodiment 2401 of FIG. 24A with at least one difference being that thedependent current supply is instead implemented to provide a currentsink signal. In an example of operation and implementation, consider DSC28-26A to be the second DSC 28 of the embodiment 2503 of FIG. 25B thatis implemented to facilitate delivery of a current sink signal tocounter the electrical impulse traveling via the extra or accessoryelectric pathway (e.g., the dependent current supply connected to anegative power supply voltage, such as −Vdd). Note that differentrespective DSCs may be implemented different purposes within particularapplication.

Referring to embodiment 2602 of FIG. 26B, this diagram is similar to theprior diagram with at least one difference being that a DSC 28-26Bemploys an analog control signal that is provided directly based on theerror signal, Ve, that is generated from the comparator 2415 to controlthe amount of current that is output from the dependent current supplyvia the single-line. Note that this diagram does not include or requirethe DAC 2462 as shown in the prior diagram.

FIGS. 27A and 27B are schematic block diagrams of other embodiments 2701and 2702 of DSCs configured simultaneously to drive and sense drivesignals to electrodes, respectively, and that include capability toprovide current source or current sink signals in accordance with thepresent invention.

Referring to embodiment 2701 of FIG. 27A, this diagram has similaritiesto the embodiment 2401 of FIG. 24A and also the embodiment of 2601 ofFIG. 26A. This diagram includes two dependent current sources that arecontrolled by the analog control signals that are generated by two DACs2462. The two DACs 2462 receive a digital signal provided from ADC 2460that is configured to generate a digital signal representation of theerror signal, Ve, that is generated from the comparator 2415. The DSC28-27A of this diagram includes capability to provide a current signalthat is operative as a current sink signal (e.g., via the dependentcurrent supply connected to a negative power supply voltages, such as−Vdd) or the current source signal (e.g., via the dependent currentsupply connected to a positive power supply voltage, such as Vdd).Generally speaking, with respect to a dependent current supply, theamount of current, i, that is output from such a dependent currentsupply based on the error signal, Ve, is a function of a programmablescale factor, k, of the dependent current supply such that: i=k×Ve.

In this diagram, consider the current sink signal to be i1=k1*Ve that isprovided from the dependent current source that is implemented toprovide a current sink signal, and consider the current source signal tobe i2=k2*Ve that is provided from the dependent current source that isimplemented to provide a current source signal (e.g., where k1 and k2are the programmable scale factors of the two respective dependentcurrent sources, which may be the same programmable scale factors, ordifferent), then the total current i3 that is delivered by the DSC28-27A of this diagram is the combination of i1 and i2 (e.g., i3=i1=i2).

Referring to embodiment 2702 of FIG. 27B, this diagram is similar to theprior diagram with at least one difference being that a DSC 28-27Bemploys an analog control signal that is provided directly based on theerror signal, Ve, that is generated from the comparator 2415 to controlthe amounts of the currents that are output from the dependent currentsupplies and combined to be provided via the single-line coupling to theelectrode 1410. Note that this diagram does not include or require thetwo DACs 2462 as shown in the prior diagram. In certain alternativeembodiments, as switches implemented such that the analog control signalis provided to only one of the two dependent current supplies as neededto adapt the drive signal, whether to provide a current sink signal or acurrent source signal to ensure that the drive signal properly tracks,follows, matches, etc. the reference signal provided to the one of theinputs of the comparator 2415.

In addition, in certain implementations, the DSC 28 services anelectrode 1410 that is operative to perform more than one operationincluding sensing of cardiac electrical activity as well as delivery ofa current sink signal in accordance with treatment of tachycardias. Incertain other implementations, the DSC 28 services an electrode 1410that is operative to perform multiple operations including sensing ofcardiac electrical activity, delivery of a current sink signal inaccordance with treatment of tachycardias, and also delivery of thepacing signal. Note that multiple respective functions and operationsmay be effectuated via a DSC 28 that services a single electrode 1410based on the total flexibility by which a reference signal may begenerated and used within a DSC as described herein. For example, anappropriately designed reference signal may be implemented to performmore than one operation via the single electrode 1410 that is servicedby a single DSC 28. Given that any of the parameters of the drive signalmay be adjusted in any desired manner (e.g., voltage level, currentlevel, pulse width, frequency, shape, etc.), a reference signal that isdesigned to serve multiple purposes may be used by a DSC 28 to generatea drive signal to perform these different operations (e.g., sensing,current sink signal, pacing signal delivery, etc.).

FIGS. 28A, 28B, and 28C are schematic block diagrams of otherembodiments 2801, 2802, and 2803 of DSCs configured simultaneously todrive and sense drive signals to electrodes, respectively, and thatinclude capability to provide differential sensing and/or stimulationacross one or more bodily portions of a subject in accordance with thepresent invention.

Referring to embodiment 2801 of FIG. 28A, one or more processing modules42 are in communication with two DSCs 28 (e.g., a first DSC 28 and asecond DSC 28). As described also with respect other embodiments,examples, diagrams, etc. herein, the one or more processing modules 42are configured to provide various signals to the DSCs 28 including oneor more of reference signals, power input, communication signals,interfacing signals, control signaling, etc. and also to receive forserious signals from the DSCs 28 including one or more of informationfrom the DSCs 28 corresponding to one or more electrical characteristicsof the signals provided from the DSCs 28 via the electrodes 1410, one ormore electrical characteristics of the electrodes 1410 themselves, oneor more electrical signals coupled into the electrodes 1410, and/orchange of any one or more of these electrical characteristics, etc.

Note that the DSCs may be implemented in any desired configurationincluding any of the variants described herein such as operating byproviding a voltage signal, current signal, a current sink or sourcesignal, etc. The two DSCs 28 operate cooperatively perform differentialsensing and/or stimulation across a particular bodily portion. Each ofthe DSCs 28 services a respective electrode 1410. Each of the respectiveDSCs 28 operates based on a different respective reference signal (e.g.,first reference signal and second reference signal). In an example ofoperation and implementation, a first reference signal that is employedby one of the DSCs 28 is 180° out of phase or an inverted version of thefirst reference signal that is employed by the other one of the DSCs 28.The two electrodes 1410 are located within a desired proximity to oneanother so as to facilitate coupling of signals between the ends of theelectrodes 1410 as they are being serviced by the DSCs 28. As electricalsignals are coupled between the ends of the electrodes 1410, the twoDSCs 28 operate cooperatively to provide signals via the two respectiveelectrodes 1410, and electric signals are coupled between the ends ofthe electrodes 1410 via the pathway between the two bodily portions(e.g., first location on bodily portion and second location on bodilyportion).

For example, to effectuate differential sensing and/or stimulationbetween the first location of other portion of the second but withportion, electrical signaling is coupled between the two ends of theelectrodes 1410 via a pathway through the subject between the ends ofthose two electrodes 1410. In a specific example, consider animplementation which a particular portion or section of the heart of thesubject is to be stimulated, then the ends of the electrodes 1410 areplaced (e.g., implanted) across that particular portion or section of aheart of the subject so that electrical signaling coupled between theends of the electrodes 1410 travels across that particular portion orsection of the heart. Again, note that the DSCs 28 are operative toperform both differential sensing and/or stimulation across a particularbodily portion such that sensing of one or more electricalcharacteristics of that particular bodily portion, between the first andsecond location, may be made simultaneously and concurrently whendelivering differential stimulation by driving an electrical signal toprovide electrical stimulation to that bodily portion. Note that theremay be applications in which only differential sensing or onlydifferential stimulation is desired, but the DSCs 28 are also operativeto perform both differential sensing and differential stimulation inalternative applications.

Referring to embodiment 2802 of FIG. 28B, this diagram has certainsimilarities to the previous diagram and provides additional detailregarding one particular manner by which the DSCs may be implemented. Inthis diagram, DSCs 28-28B are implemented similarly to the DSC 28-24A orDSC 28-24B of FIGS. 24A and 24B, respectively. Note that the DSCs 28-28Bmay be implemented without the DAC 2462 in certain implementations suchthat the analog control signal is provided directly based on the errorsignal, Ve, that is generated from the comparator 2415 to control theamounts of the current that is output from the dependent current supplyand provided via the single-line coupling to the electrode 1410.

In an example of operation and implementation, a first reference signalthat is employed by one of the DSCs 28-28B is 180° out of phase or aninverted version of the first reference signal that is employed by theother one of the DSCs 28-28B. As with respect to the previous diagram,the two electrodes 1410 are located within a desired proximity to oneanother so as to facilitate coupling of signals between the ends of theelectrodes 1410 as they are being serviced by the DSCs 28-28B. Aselectrical signals are coupled between the ends of the electrodes 1410,the two DSCs 28-28B operate cooperatively to provide signals via the tworespective electrodes 1410, and electric signals are coupled between theends of the electrodes 1410 via the pathway between the two bodilyportions (e.g., first location on bodily portion and second location onbodily portion). Note that such cooperative operation between therespective electrodes 1410 and the signals driven via them by theirrespective DSCs 28-28B are operative to facilitate differential sensingand/or differential stimulation as may be desired in variousapplications.

Referring to embodiment 2803 of FIG. 28C, this diagram is similar to theprior previous diagram with certain differences being that thecommunication between the one or more processing modules 42 and DSCs28-28C are made via respective communication pathways that include anynumber of communication channels, pathways, etc. (e.g., generally n,where n is a positive integer greater than or equal to 1) such that thedigital information corresponding to one or more electricalcharacteristics of the signals provided from the DSCs 28 via theelectrodes 1410, one or more electrical characteristics of theelectrodes 1410 themselves, one or more electrical signals coupled intothe electrodes 1410, and/or change of any one or more of theseelectrical characteristics, etc. from the ADCs 2460 are provided viathese respective communication pathways. Also, the reference signalsprovided to comparators 2415 of the DSCs 28-28C are provided from theone or more processing modules 42 via these respective communicationpathways as well. For example, rather than the information correspondingto one or more electrical characteristics of the signals provided fromthe DSCs 28 via the electrodes 1410, one or more electricalcharacteristics of the electrodes 1410 themselves, one or moreelectrical signals coupled into the electrodes 1410, and/or change ofany one or more of these electrical characteristics, etc. being providedvia a direct connection from the ADCs 2460 of the DSCs 28-28C, they areprovided via these respective communication pathways. Similar to theprevious diagram and others that are implemented to facilitatedifferential sensing and/or stimulation a first reference signal that isemployed by one of the DSCs 28-28C is 180° out of phase or an invertedversion of the first reference signal that is employed by the other oneof the DSCs 28-28C. Also, as with respect to previous diagrams, the twoelectrodes 1410 are located within a desired proximity to one another soas to facilitate coupling of signals between the ends of the electrodes1410 as they are being serviced by the DSCs 28-28C.

FIGS. 29A and 29B are schematic block diagrams of embodiments 2901 and2902 of sheaths that are serviced by DSCs that are operativesimultaneously to drive and sense drive signals to electrodes,respectively, and that also includes capability to provide single-endedor differential sensing and/or stimulation across one or more bodilyportions of a subject in accordance with the present invention.

Referring to embodiment 2901 of FIG. 29A, a sheath 2911 includesmultiple respective sensing and/or stimulation conductive points. Notethat the conductive points may be implemented using any desiredconductive material (e.g., any type of metal such as copper, aluminum,platinum, gold, silver, iron, steel, brass, graphite, graphite, and/orany other material having electrically conductive properties). Each ofthe respective sensing and/or stimulation conductive points of thesheath 2911 is coupled via a respective electrode 1410 to correspondingDSC 28. As with respect to other diagrams herein, the DSCs 28 are incommunication with one or more processing modules 42 via one or morecommunication channels, pathways, etc. (e.g., generally n, where n is apositive integer greater than or equal to 1). Examples of one or moresignals that may be provided between the DSCs 28 and the one or moreprocessing modules 42 to the DSC may include any one or more of areference signal such as provided from the one or more processingmodules 42 to one or more of the DSCs 28 (e.g., referred to as Vref incertain diagrams), power input, communication signaling, interfacing,control signaling, digital information provided from the DSC 28 to theone or more processing modules 42, digital information provided from theone or more processing modules 42 to the DSC 28, etc.

The sheath 2911 includes the integrated sensing and/or stimulationconductive points that are operative to facilitate bodily sensing and/orstimulation of the subject based on a particular bodily portion of thesubject with which the sheath 2911 is in contact or wrapped around. Notethat the sheath 2911 may be implemented in a variety of ways. Forexample, the sheath 2911 may be constructed of a rigid material having aparticular shape, such as flat or curved or any desired shape, such thata rigid sheath is placed in contact with a bodily portion of the subjectto facilitate sensing and/or stimulation via the sensing and/orstimulation conductive points of the rigid sheath. In another example,the sheath 2911 may be constructed of a flexible material and/or awrap-able material that may be wrapped around a bodily portion of thesubject, such as around a portion of the abdomen, a leg, an arm, forget,etc. of the subject. In certain implementations, such a flexible and/orwrap-able sheath may include one or more means to fasten the sheath 2911and hold it in place at a desired location with respect to the subject.Examples of such fastening means may include Velcro, straps, buttons,etc. and/or any desired means to keep the sheath 2911 in a desiredlocation with respect to a bodily portion of the subject.

Note also that the sheath 2911 may include any desired number of sensingand/or stimulation conductive points arranged in any desired pattern.One example of a pattern includes a rectangular shaped matrix of sensingand/or stimulation conductive points as shown in the diagram; however,any other desired pattern may alternatively be used. Other patterns mayinclude the sensing and/or simulation conductive points arranged in asquare shaped pattern, triangular pattern, circular pattern, etc. and/orany other desired pattern. Also, note that sheath 2911 may be of anydesired size and shape itself. The sheath 2911 shown in the diagram is asubstantially rectangular shaped sheath 2911 with rounded corners;however, any desired alternative shape may alternatively be used for thesheath 2911.

In an example of operation and implementation, the DSCs 28 are coupledrespectively via electrodes 1410 to different respective sensing and/orstimulation conductive points of the sheath 2911. For example, a firstDSC 28 is coupled via a first electrode 1410 to a first sensing and/orstimulation point of the sheath 2911. A second DSC is coupled via asecond electrode 1410 to a second sensing and/or stimulation point ofthe sheath 2911, and so on such that the DSCs 28 are coupledrespectively via electrodes 1410 to the different respective sensingand/or stimulation conductive points of the sheath 2911 on a one-to-onebasis such that each respective DSC 20 services a respective sensingand/or stimulation point of the sheath 2911.

In an example of operation and implementation, the electrical signalsprovided from the DSCs 28 that are coupled via the respective electrodes1410 to the sensing and/or stimulation conductive points of the sheath2911 are coupled from the sensing and/or stimulation conductive pointsof the sheath 2911 into a bodily portion of the subject that is inproximity to or in contact with the sheath 2911. Considering anapplication of stimulation, such as in rehabilitation of injured muscleof the subject (e.g., such as a torn hamstring of an athlete),electrical stimulation is provided from the stimulation conductivepoints of the sheath 2911 to all or a desired portion of the injuredmuscle of the subject to assist in the rehabilitation and recovery ofthe injured muscle of the subject. Note that the electrical signalingprovided via the stimulation conductive points of the sheath 2911 may becontrolled in any desired manner based on the flexibility and control ofthe signaling that may be provided from the respective DSCs 28.

In one example, electrical stimulation is provided via electricalsignals from the stimulation conductive points of the sheath 2911 in auniform manner across all of the stimulation conductive points of thesheath 2911 such that all of the electrical signals are of the same type(e.g., having the same electrical characteristics including one or moreof synchronized in time, in phase with one another, same magnitude, samefrequency if not DC signals, etc.). In another example, electricalstimulation is provided in a time varying manner via electrical signalsthat are non-uniform across the stimulation conductive points of thesheath 2911 (e.g., having different electrical characteristics includingone or more of being non-synchronous signals, out of phase with oneanother, of different magnitudes, different frequencies if not DCsignals, etc.).

In yet another example, electrical stimulation is provided in a timevarying manner such that waves of electrical stimulation are providedacross the bodily portion of the subject that is in proximity with or incontact with the sheath 2911. For example, consider electricalstimulation starting on the leftmost column of the stimulationconductive points of the sheath 2911 and propagating column by column tothe right on a periodic basis, such that electrical stimulation is firstprovided you the leftmost column, then the column to the right of thatone, then to the next column to the right of that one, and so on untilthe rightmost column of the sheath 2911 provides electrical stimulation,and then the process begins again with the leftmost, of the stimulationconductive points of the sheath 2911. Alternatively, such stimulationcould begin on the right of the sheath 2911 and propagate towards theleft of the sheath 2911. Similarly, such electrical stimulation may beprovided via respective rows of the stimulation conductive points of thesheath 2911 as well, such as starting from top towards bottom orb, orvice versa. In yet another example, electrical stimulation is providedany electrical stimulation pattern manner starting by using theoutermost stimulation conductive points of the sheath 2911, then byusing the stimulation conductive points of the sheath 2911 that arelocated within a first perimeter formed by the outermost stimulationconductive points of the sheath 2911, and then by using the stimulationconductive points of the sheath that are located within a secondperimeter of stimulation conductive points of the sheath 2911, and so onsuch that, as a function of time, the electrical stimulation provided bythe sheath 2911 becomes more and more concentrated toward the centerstimulation conductive points of the sheath 2911. Generally speaking,any desired manner of electrical stimulation may be at performed usingthe stimulation conductive points of the sheath 2911 given that therespective signals provided from the DSCs 28 via the electrodes 1410 tothe stimulation conductive points of the sheath 2911 may be generated inany desired manner. Given the total flexibility by which a referencesignal may be generated and used within the DSC 28 as described herein(e.g., such as using signal generator or within one or more processingmodules 42), any of the parameters of the stimulation sensing and/orstimulation signals including any one or more of voltage level, currentlevel, pulse width, frequency, shape, etc. may be adjusted to anydesired value with extremely fine resolution and accuracy.

Referring to embodiment 2902 of FIG. 29B, the sheath 2912 includesdifferential pairs of sensing and/or simulation conductive points thatare serviced via DSCs 28 that couples to them via electrodes 1410. Aswith respect to other diagrams herein, the DSCs 28 are in communicationwith one or more processing modules 42 via one or more communicationchannels, pathways, etc. (e.g., generally n, where n is a positiveinteger greater than or equal to 1). In this diagram, respective pairsof sensing and/or stimulation conductive points operate cooperatively tofacilitate differential sensing and/or stimulation via the sheath 2912that is operative to be in proximity to or in contact with a bodilyportion of the subject.

For example, a first DSC 28 services, via a first electrode 1410, afirst point of a first differential pair of sensing and/or simulationconductive points of the sheath 2912, and a second DSC 28 services, viaa second electrode 1410, a second point of the first differential pairof sensing and destination conductive points of the sheath 2912. Thisfirst and second conductive points of the first differential pair ofsensing and/or stimulation conductive points operate cooperatively basedon the electrical signaling provided to them via the electrodes 1410 andthe first DSC 28 and the second DSC 28. Similar to the differentialsensing and/or stimulation is described elsewhere herein, the use of thedifferential pairs of sensing and/or simulation conductive points of thesheath 2912 facilitate very localized and controlled sensing and/orsimulation across a particular desired bodily portion of the subjectbetween the two sensing and/or stimulation conductive points of thedifferential pair of sensing and/or stimulation conductive points.Similarly, a third DSC 28 services, via a third electrode 1410, a firstpoint of a second differential pair of sensing and/or simulationconductive points of the sheath 2912, and a fourth DSC 28 services, thea fourth electrode 1410, a second point of the second differential pairof sensing and/or stimulation conductive points of the sheath 2912.Additionally, other DSCs 28 respectively service, via other electrodes1410, the other respective conductive points within the otherdifferential pairs of sensing and/or stimulation conductive points ofthe sheath 2912.

Similar to the sheath 2912 of the previous diagram, the sheath 2912includes the integrated sensing and/or stimulation conductive points indifferent pairs that operate cooperatively and that are operative tofacilitate bodily sensing and/or stimulation of the subject based on aparticular bodily portion of the subject with which the sheath 2912 isin contact or wrapped around. Also, note that the sheath 2912 may beimplemented in a variety of ways similar to the sheath 2911 (e.g.,constructed of a rigid material having a particular shape, such as flator curved or any desired shape, such that a rigid sheath is placed incontact with a bodily portion of the subject to facilitate sensingand/or stimulation via the sensing and/or stimulation conductive pointsof the rigid sheath or constructed of a flexible material and/or awrap-able material that may be wrapped around a bodily portion of thesubject, may include one or more means to fasten the sheath 2912 andhold it in place at a desired location with respect to the subject).

Note also that the sheath 2912 may include any desired number ofdifferential pairs of sensing and/or stimulation conductive pointsarranged in any desired pattern or arrangement (e.g., triangular,square, circular, oval, etc.). One example of a pattern or arrangementincludes a rectangular shaped matrix of sensing and/or stimulationconductive points as shown in the diagram such that the differentialpairs of sensing and/or stimulation conductive points are alignedhorizontally. Generally speaking, any other desired pattern orarrangement may alternatively be used. Also, similar with respect to thesheath 2911 of the previous diagram, note that sheath 2912 may be of anydesired size and shape itself. The sheath 2912 shown in the diagram is asubstantially rectangular shaped sheath 2912 with rounded corners;however, any desired alternative shape may alternatively be used for thesheath 2912.

In an example of operation and implementation, the DSCs 28 are coupledrespectively via electrodes 1410 to different respective sensing and/orstimulation conductive points of the different respective differentialpairs of sensing and/or stimulation conductive points of the sheath2912. For example, a first DSC 28 is coupled via a first electrode 1410to a first sensing and/or stimulation point of a first differential pairof sensing and/or stimulation conductive points of the sheath 2912. Asecond DSC is coupled via a second electrode 1410 to a second sensingand/or stimulation point the first differential pair of sensing and/orstimulation conductive points of the sheath 2912, and so on such thatthe DSCs 28 are coupled respectively via electrodes 1410 to thedifferent respective sensing and/or stimulation conductive points ofeach of the differential pairs of sensing and/or stimulation conductivepoints of the sheath 2912 on a one-to-one basis such that eachrespective DSC 20 services a respective sensing and/or stimulation pointof the sheath 2912.

In an example of operation and implementation, a first reference signalthat is employed by one of the DSCs 28 that services a first point of afirst differential pair of sensing and/or stimulation conductive pointsis 180° out of phase or an inverted version of the first referencesignal that is employed by the other one of the DSCs 28 that services asecond point of the first differential pair of sensing and/orstimulation conductive points. The two conductive points of the point ofa first differential pair of sensing and/or stimulation conductivepoints are spaced apart by a desired proximity to one another so as tofacilitate coupling of signals between them based on the signaling thatis provided to them by the DSCs 28 that service them 28. As electricalsignals are coupled between the two conductive points of the point of afirst differential pair of sensing and/or stimulation conductive points,the two DSCs 28 operate cooperatively to provide signals via the tworespective electrodes 1410, and electric signals are coupled between thetwo conductive points of the point of a first differential pair ofsensing and/or stimulation conductive points via the pathway between thetwo bodily portions (e.g., first location on bodily portion and secondlocation on bodily portion).

Similar to the sheath 2911, note also that the sheath 2912 may includeany desired number of differential pairs of sensing and/or stimulationconductive points, and the sheath 2912 may have any desired size andshape. Note also that the respective spacing between the sensing and/orstimulation conductive points of the differential pairs of sensingand/or stimulation conductive points may be uniform throughout the sheet2912, or they may be different. For example, note that a firstdifferential pair of sensing and/or stimulation conductive points of thesheath 2912 may be separated by a first distance, and a seconddifferential pair of sensing and/or stimulation conductive points of thesheath 2912 may be separated by a second distance that is different thanthe first distance. Generally speaking, the different respectivedifferential pairs of sensing and/or submission conductive points of thesheath 2912 may be implemented according to any desired pattern orarrangement, spacing, etc. in certain examples, the spacing between theconductive points of the differential pairs of sensing and/orstimulation conductive points is selected based on the signaling to beprovided to them so as to facilitate coupling of electrical signalsbetween the two conductive points of a differential pair of sensingand/or stimulation conductive points. For example, a larger distancebetween the two conductive points of a differential pair of sensingand/or stimulation conductive points may be made when higher levels ofsignaling (e.g., higher magnitude of voltage and/or current) as opposedto lower levels of signaling (e.g., lower magnitude of voltage and/orcurrent) that are insufficient to facilitate coupling between the twoconductive points of the differential pair of sensing and/or stimulationconductive points. In addition, note that the electrical stimulationprovided via the sheath 2912 may be performed uniformly, nonuniformly,time varying, patterned or wave driven, etc. similarly as describedabove with respect to the sheath 2911 of the previous diagram.

FIG. 29C is a schematic block diagram of an embodiment 2903 of a sheathshowing connectivity of electrodes to the sensing and/or stimulationconductive points of the sheath in accordance with the presentinvention. This diagram shows a side view of a sheath 2913 that includessensing and/or stimulation conductive points. The sheath 2913 includesan interface that couples electrodes (e.g., such as electrodes 1410 thatare respectively serviced by different DSCs 28 as described with respectto other diagrams herein) to the sensing and/or stimulation conductivepoints of the sheath 2913. In addition, within the sheath 2913, thesensing and/or stimulation conductive points of the sheath 2913 areimplemented and respectively surrounded by electrical insulation betweenthem to impede or stop any coupling of electrical signals between thewires or electrodes that connect couple from the interface to therespective sensing and or submission conductive points of the sheath2913. The electrical insulating material may be of any desired type.Examples of electrical insulating material may include any one or moreof glass, paper, Teflon, rubber-like polymers, plastics, fiberglass,porcelain, and/or any other material having electrically insulatingproperties. Electrical connection is made within the sheath 2913 viawires, electrodes, or other means from the interface of the sheath 2913and through the electrical insulation of the sheath 2913 to thedifferent sensing and/or stimulation conductive points of the sheath2913. Separating the respective sensing and/or stimulation conductivepoints of the sheath 2913 from one another spatially and alsoelectrically insulating them from one another provides the ability toensure very localized control of the sensing and/or stimulation to beperformed via the respective sensing and/or stimulation conductivepoints of the sheath 2913.

In addition, with respect to other embodiments, note that other designconsiderations may be employed to facilitate electrical insulationbetween the sensing and/or stimulation conductive points of a sheath.For example, they may be spatially separated such that there is littleto no electrical coupling between them, if no electrical coupling isdesired between them in certain embodiments. In certain embodiments,when operating one or more DSCs to provide AC signaling, the crosscoupling between the respective sensing and/or stimulation points wouldbe based on capacitive coupling, especially when using higher frequencyAC signaling.

FIG. 29D includes schematic block diagrams of embodiments 2904 and 2905of sheaths that are operative to facilitate sensing and/or stimulationacross one or more bodily portions of a subject in accordance with thepresent invention. Note that the respective sheaths 2914-1, 2914-2,2914-3, 2914-4, and 2914-5 may be implemented in and any number ofdifferent ways including the sensing and/or stimulation conductivepoints are individually serviced by respective DSCs such as with respectto FIG. 29A, the sensing and/or stimulation conductive points areimplemented in differential pairs such as respective FIG. 29B, etc.Also, note that the respective sheaths 2914-1, 2914-2, 2914-3, 2914-4,and 2914-5 may be constructed of any types of materials including rigidmaterial, flexible material, etc., and they may have any desired shape.

Referring to embodiment 2904, the sheath 2914-1 is shown as being incontact with or wrapped around the bicep of the subject. Sheath 2914-2is shown as being in contact with the wraparound a quadricep of thesubject.

Referring to embodiment 2905, sheath 2914-3 is shown as being in contactwith or wrapped around a portion of the head of the subject, such asaround for head. Sheath 2914-4 is shown as being in contact with orwrapped around the chest or thorax of a subject. Sheath 29 1405 is shownas being in contact with the wraparound the abdomen of the subject.

In addition, note that in certain implementations that performdifferential sensing and/or stimulation, the pairing of two conductivepoints of a particular differential pair of sensing and/or stimulationconductive points is implemented such that the differential sensingand/or stimulation is made through a particular bodily portion of thesubject. For example, when the sheath is in contact with the wraparounda bodily portion of the subject (e.g., around the bicep or quadricep),the two conductive points of a particular differential pair of sensingand/or stimulation conductive points may be located oppositely withrespect to that bodily portion of the subject so that the differentialsignaling travels through that particular bodily portion of the subject(e.g., through the bicep or quadricep).

In other implementations that perform differential sensing and/orstimulation, the pairing of two conductive points of a particulardifferential pair of sensing and or stimulation conductive points isimplemented such that the differential sensing and/or stimulation ismade across the surface of skin and/or within the bodily portion justbelow the surface of the skin between the two conductive points of adifferential pair of sensing and/or stimulation conductive points (e.g.,Based on the electrical signals coupling between the two conductivepoints of the differential pair of sensing and/or stimulation conductivepoints and also coupling into that bodily portion of the subject).

In addition, note that two different sheaths located on opposite sidesof a bodily portion of the subject may be implemented to operatecooperatively with one another. For example, consider a first sheathlocated on the front of the chest or thorax of a subject and a secondsheath located on the back of the subject that operate cooperatively oneanother such that electrical signaling is transmitted from the firstsheath and received via the seconds sheath.

In an example of operation and implementation, an electrical stimulationsystem includes sheath (e.g., such as in any of the FIG. 29A, 29B, 29C,or 29D). The sheath includes conductive points that are operative tofacilitate electrical stimulation to a bodily portion of a user. Inaddition, the electrical stimulation system includes drive-sensecircuits (DSCs) 28 operably coupled to the conductive points of thesheath via electrodes 1410. Note that the DSCs are configured togenerate electrical stimulation signals based on reference signals. Theelectrical stimulation signals are coupled into the bodily portion ofthe user via the conductive points of the sheath. When enabled, a firstDSC is configured to provide a first electrical stimulation signal via afirst electrode to a first conductive point of the sheath. The firstelectrical stimulation signal is coupled into a first location of thebodily portion of the user that is in proximity to or in contact withthe first conductive point of the sheath. Also, the first DSC isconfigured to sense, via the first conductive point of the sheath andvia the first electrode, a first change of the first electricalstimulation signal based on coupling of the first electrical stimulationsignal into the first location of the bodily portion of the user. Thefirst DSC is also configured to generate a first digital signal that isrepresentative of the first change of the first electrical stimulationsignal.

Similarly, when enabled, a second DSC is configured to provide a secondelectrical stimulation signal via a second electrode to a secondconductive point of the sheath. The second electrical stimulation signalis coupled into a second location of the bodily portion of the user thatis in proximity to or in contact with the second conductive point of thesheath. The second DSC is also configured to sense, the secondconductive point of the sheath and via the second electrode, a secondchange of the second electrical stimulation signal based on coupling ofthe second electrical stimulation signal into the second location of thebodily portion of the user. Also, the second DSC is configured togenerate a second digital signal that is representative of the secondchange of the second electrical stimulation signal.

The electrical stimulation system also includes one or more processingmodules that includes and/or is coupled to memory that storesoperational instructions. The one or more processing modules is operablycoupled to the DSCs. When enabled, the one or more processing modules isconfigured to execute the operational instructions to generate theplurality of reference signals and to process digital signals generatedby the DSCs including the first digital signal generated by the firstDSC and the second digital signal generated by the first DSC todetermine a response profile of one or more electrical characteristicsof the bodily portion of the user. Note that the response profile of oneor more electrical characteristics of the bodily portion of the user maycorrespond to a variety of types. For example, the response profile ofone or more electrical characteristics of the bodily portion of the usermay correspond to any one or more of an impedance (Z) profile of thebodily portion of the user, a voltage of the bodily portion of the user,a current profile of the bodily portion of the user, cardiac electricalactivity of the bodily portion of the user, electrical signal couplinginto or from the of the bodily portion of the user, etc.

In certain examples, the sheath is implemented with a rigid materialthat is shaped to interface with the bodily portion of the user. Inother examples, the sheath is implemented with a flexible and wrap-ablematerial that is operative to be placed against the bodily portion ofthe user. If desired, the sheath also includes one or more fasteners tokeep sheath in place against the bodily portion of the user.

In even other examples, the first electrical stimulation signal is 180degrees out of phase to the second electrical stimulation signal, andthe first conductive point of the sheath and the second conductive pointof the sheath operate cooperatively to provide differential electricalstimulation between the first location of the bodily portion of the userand the second location of the bodily portion of the user. Also, notethat the electrodes may be electrically isolated from each other withinthe sheath by an electrically insulating material such as described withreference to FIG. 29C. Note also that the bodily portion of the user maybe any bodily portion. Some possible bodily portions include a leg, anarm, abdomen, chest or thorax, or head of the user.

Note also that the conductive points of the sheath may be arranged inany desired pattern or arrangement. One specific pattern or arrangementincludes a matrix pattern including rows of conductive points andcolumns of conductive points. In an example of operation andimplementation, when enabled, the DSCs is configured to provide theplurality of electrical stimulation signals via the plurality ofelectrodes to the plurality of conductive points, including the firstelectrical stimulation signal via the first electrode to the firstconductive point of the sheath and the second electrical stimulationsignal via the second electrode to the second conductive point of thesheath, such that electrical stimulation is provided sequentially andsuccessively via the rows of conductive points or via the columns ofconductive points such that a first row or first column of theconductive points provide electrical stimulation at or during a firsttime and a second row or second column of the conductive points provideelectrical stimulation at or during a second time that follows the firsttime.

Note that the DSCs may be implemented in any of a variety of waysincluding as described herein in various examples, embodiments, etc. Inone example, the first DSC includes a power source circuit operablycoupled via a single line to the first electrode that couples to thefirst conductive point. When enabled, the power source circuit isconfigured to provide an analog signal via the single line coupling tothe first electrode that couples to the first conductive point. Theanalog signal includes at least one of a DC (direct current) componentor an oscillating component. The first DSC also includes a power sourcechange detection circuit operably coupled to the power source circuit.When enabled, the power source change detection circuit is configured todetect an effect on the analog signal that is based on coupling of thefirst electrical stimulation signal into the first location of thebodily portion of the user and to generate the first digital signal thatis representative of the first change of the first electricalstimulation signal.

In addition, in some specific examples, the power source circuit isimplemented to include a power source to source at least one of avoltage or a current via the single line to the first electrode thatcouples to the first conductive point. The power source change detectioncircuit also includes a power source reference circuit configured toprovide at least one of a voltage reference or a current reference. Thepower source change detection circuit also includes a comparatorconfigured to compare the at least one of the voltage and the currentprovided via the single line to the first electrode that couples to thefirst conductive point to the at least one of the voltage reference andthe current reference to produce the analog signal.

In another example of operation and implementation, an electricalstimulation system includes a sheath that includes conductive pointsthat are operative to facilitate electrical stimulation to a bodilyportion of a user. The electrical stimulation system includesdrive-sense circuits (DSCs) operably coupled to the conductive points ofthe sheath via electrodes. The DSCs are configured to generate aelectrical stimulation signals based on reference signals. Theelectrical stimulation signals are coupled into the bodily portion ofthe user via the conductive points of the sheath. When enabled, a DSC isconfigured to provide an electrical stimulation signal via an electrodeto a conductive point of the sheath, wherein the electrical stimulationsignal is coupled into a location of the bodily portion of the user thatis in proximity to or in contact with the conductive point of thesheath. The DSC is also configured to sense, via the conductive point ofthe sheath and via the electrode, a change of the electrical stimulationsignal based on coupling of the electrical stimulation signal into thelocation of the bodily portion of the user. The DSC is also configuredto generate a digital signal that is representative of the change of theelectrical stimulation signal.

In addition, when enabled, the plurality of DSCs is configured toprovide the electrical stimulation signals via the electrodes to theconductive points sequentially and successively via respective subsetsof the conductive points that each include fewer than all of theconductive points such that a first subset of conductive points provideelectrical stimulation at or during a first time and a second subset ofconductive points provide electrical stimulation at or during a secondtime that follows the first time.

The electrical stimulation system also includes one or more processingmodules that includes and/or is coupled to memory that storesoperational instructions. The one or more processing modules is operablycoupled to the DSCs. When enabled, the one or more processing modules isconfigured to execute the operational instructions to generate thereference signals and to process digital signals generated by theplurality of DSCs including the digital signal generated by the DSC todetermine a response profile of one or more electrical characteristicsof the bodily portion of the user.

In certain examples, the conductive points of the sheath are arranged ina matrix pattern including rows of conductive points and columns ofconductive points. The first subset of conductive points includes afirst row of conductive points, and the second subset of conductivepoints includes a second row of conductive points.

FIG. 29E includes schematic block diagrams of embodiments of sheathsthat are operative to facilitate sensing and/or stimulation across oneor more bodily portions of a subject to perform trend tracking based onbilateral symmetry comparative analysis in accordance with the presentinvention.

Referring to the embodiment 2906, this diagram shows two sheaths 2914-2as being in contact with or wrapped around the quadriceps of thesubject. In an example of operation and implementation, consider aninstance in which one of the quadriceps of the subject is healthy andthe other is undergoing rehabilitation, such as after an injury,overexertion, and/or other event(s) that caused some distress to one ofthe quadricep. By employing to separate sheaths that each respectivelyare serviced by DSCs, in communication with one or more processingmodules, etc., sensing, stimulation, and/or impedance sensing may beperformed with respect to one of the quadriceps, such as the oneundergoing rehabilitation, based on sensing, stimulation, and/orimpedance sensing with respect to the other of the quadriceps. Suchsensing, stimulation, and/or impedance sensing with respect to thehealthy quadricep may be used to determine status regarding therehabilitation of the other quadricep. For example, comparison of thehealthy quadricep as a baseline to be used to determine whether or notthe quadricep undergoing rehabilitation is progressing satisfactorily orhas fully been rehabilitated.

Referring to the embodiment 2907, this diagram is similar to theprevious one yet shows two sheaths 2914-2 as being in contact with orwrapped around the biceps of the subject. In an example of operation andimplementation, consider an instance in which one of the biceps of thesubject is healthy and the other is undergoing rehabilitation, such asafter an injury, overexertion, and/or other event(s) that caused somedistress to one of the bicep. By employing to separate sheaths that eachrespectively are serviced by DSCs, in communication with one or moreprocessing modules, etc., sensing, stimulation, and/or impedance sensingmay be performed with respect to one of the biceps, such as the oneundergoing rehabilitation, based on sensing, stimulation, and/orimpedance sensing with respect to the other of the biceps. Such sensing,stimulation, and/or impedance sensing with respect to the healthy bicepmay be used to determine status regarding the rehabilitation of theother bicep. For example, comparison of the healthy bicep as a baselineto be used to determine whether or not the bicep undergoingrehabilitation is progressing satisfactorily or has fully beenrehabilitated.

Note that the examples of quadricep and bicep are not exhaustive of suchsensing, stimulation, and/or impedance sensing that may be performedwith respect to one bodily portion of the subject and used in comparisonto another bodily portion of the subject based on bilateral symmetry ofthe subject. For example, similar sensing, stimulation, and/or impedancesensing could also be performed with respect to the calves, knees,elbows, forearms, wrists, shoulders, etc. of the subject. In certainexamples, consider it the subject being an athlete who has suffered aninjury in an athletic competition or practice, such as with respect to abodily portion of the subject on one side of the body that has acorresponding other bodily section on the other side of the body due tothe bilateral symmetry of the subject. Such sensing, stimulation, and/orimpedance sensing based on one of the bodily portions such as serving asa baseline may be used to determine the efficacy of the sensing,stimulation, and/or impedance sensing of another bodily portion based onthe bilateral symmetry of the subject.

FIG. 29F includes schematic block diagrams of an embodiment 2908 of oneor more sheaths that are operative to facilitate sensing and/orstimulation across one or more bodily portions of a subject duringphysical activity including adaptation thereof in accordance with thepresent invention. Note that such a sheath 2914-1 that is in contactwith or wrapped around the bicep to the subject or a sheath 2914-2 thatis in contact with the wrapped around the quadricep of the subject. Notethat other examples of a sheath may be implemented with respect to oneor more other bodily portions of the subject.

In an example of operation and implementation, the subject isinteractive with exercise equipment. Examples of such exercise, mayinclude any one or more of the treadmill, elliptical trainer, atreadmill, a stationary bike, etc. In many such exercise equipmentincludes a control console. In certain examples, a control console isimplemented to include functionality of the computing device. Suchfunctionality may include functionality of various embodiments ofcomputing devices described herein, such as computing device 12 of FIG.2, computing device 14 of FIG. 3, computing device 18 of FIG. 4, amongothers, as described herein.

In an example of operation and implementation, the one or more sheathsare in contact with her wrapped around one or more bodily portions ofthe subject to perform sensing, stimulation, and/or impedance sensing ofone or more bodily portions of the subject as the subject is interactingwith the exercise government. For example, during an exercise programbeing conducted with the exercise equipment, one or more DSCs serviceone or more sensing and/or stimulation conductive points of the one ormore sheaths to facilitate sensing, stimulation, and/or impedancesensing of one or more bodily portions of the subject as the subject isinteracting with the exercise government. Note that the one or more DSCsare in communication with one or more processing modules as well. Notethat all such electrical components may be implemented within thecontrol console of the exercise equipment, with electrodes connectingthe DSCs within the control console to the sensing and/or stimulationconductive points of the one or more sheaths.

In certain examples, note that the stimulation being provided to thesubject may be modified and adapted based on bodily condition, status,etc. such as heart rate, respiratory rate, change of impedance, etc. ofthe subject. In addition, and certain other examples, note that thestimulation being provided the subject may be modified and adapted basedon the particular point in an exercise program that is being provided bythe exercise equipment (e.g., as controlled by the control console) forconsumption by the subject. For example, consider an exercise equipmentof a stair master, and exercise program is may be provided forconsumption by the subject such that the exercise program varies overthe course of the exercise program (e.g., providing the effect ofsteeper or less steep inclines to be climbed over time, providing theeffect of walking along a flat surface, providing the effect of walkingdown the hill of a particular steepness, etc.) as may be desired, thesensing, stimulation, and/or impedance sensing of one or more bodilyportions of the subject as the subject is interacting with the exercisegovernment may be modified during the subject interactivity with theexercise equipment, in real time, based on the number of considerationsincluding the bodily status or response of the subject, the status orpoint within an exercise program of the exercise equipment, etc.

FIG. 29G includes schematic block diagrams of an embodiment 2909 of asheath that is in communication with a control console in accordancewith the present invention. This diagram shows an example of a sheath2914-10 that includes a power source 2990, such as a battery, or someother energy storage device such as a capacitor capable of storing ahigh degree of charge to provide power to one or more processing modules42. In certain examples, the power source 2990 also provides power toone or more DSCs 28 that service the sensing and/or stimulationconductive points of the sheath 2914-10. However, note that the one ormore processing modules 42 may be implemented to provide power to theone or more DSCs 28 that service the sensing and/or stimulationconductive points of the sheath 2914-10 in other examples. The sheath2914-10, via the one or more processing modules 42, includesfunctionality to support communication via one or more communicationlinks to a control console.

In certain embodiments, note that the control console is that ofexercise equipment such as described with respect to the previousdiagram. In certain examples, a control console is implemented toinclude functionality of the computing device. Such functionality mayinclude functionality of various embodiments of computing devicesdescribed herein, such as computing device 12 of FIG. 2, computingdevice 14 of FIG. 3, computing device 18 of FIG. 4, among others, asdescribed herein. In this diagram, the control console also includes acommunication interface 2971 that is in communication with one or moreprocessing modules 42. Note that the communication interface 2971includes functionality of a transmitter TX 2972 and a receiver TX 2973.

In certain examples, the communication facilitated between the controlconsole (e.g., computing device 12-29) and the sheath 2914-10 isperformed using wireless communication means. For example, suchcommunication may be facilitated via Bluetooth, WiFi, cellular, and/orany other wireless communication means etc. including any proprietarywireless communication means. Such an implementation provides theability for the sheath 2914-10 to operate without the necessity of anywires connecting between it and the control console. For example,information may be provided between the respective one or moreprocessing modules of the sheath 2914-10 and the control console viawireless communication means thereby freeing up the user who isinteracting with the exercise equipment. In addition, note that such asheath 2914-10 may be employed to facilitate sensing, stimulation,and/or impedance sensing of one or more bodily portions of a subjecteven when not specifically interacting with exercise equipment. In anexample of operation and implementation, a computing device issupporting wireless communication with the sheath 2914-10 as the subjectis doing calisthenics, running in place, doing sit-ups, running aroundthe track that is within a sufficient range in proximity such thatwireless communication may be supported between the computing device andthe sheath 2914-10, etc.

FIG. 30 is a schematic block diagram of an embodiment 3000 of one ormore electrodes that are serviced by one or more DSCs that includescapability to provide single-ended or differential sensing and/orstimulation across one or more bodily portions of a subject inaccordance with the present invention. This diagram shows multipleelectrodes 1410 that are in proximity to or in contact with the skinsurface of a subject and/or implanted into one or more bodily sectionsof the subject. The electrodes 1410 are serviced respectively by DSCs28, such that a first DSC 28 services a first electrode 1410 that isassociated with a first contact point (e.g., in proximity to or incontact with a first contact point of the skin surface of a subjectand/or a first implanted contact point of a bodily section of thesubject), a second DSC 28 services a second electrode 1410 that isassociated with a second contact point (e.g., in proximity to or incontact with a second contact point of the skin surface of a subjectand/or a second implanted contact point of a bodily section of thesubject), and so on.

Having individual respective electrodes 1410 in comparison to the sheaththat includes sensing and/or stimulation conductive points provides adifferent manner of implementation to provide sensing and/or stimulationto one or more bodily sections of the subject. Certain applications maybe more well suited for sensing and/or stimulation using a sheath, andother applications may be more well suited for sensing and/orstimulation using individual respective electrodes 1410. this diagramshows the electrodes being in proximity to one contact with the skinsurface of the chest or thorax bodily section of the subject and/orimplanted into the body of the subject in the general location of thechest or thorax (e.g., such as implanted into the chest for any of anumber of purposes such as providing a pace signal to the heart,detecting cardiac electrical activity, measuring impedance of the heartor one or more other bodily sections of the chest or thorax, etc.).

Again, note that the DSCs 28 may be implemented to perform a number offunctions with respect to providing electrical signaling to the subject(e.g., providing electrical stimulation to one or more bodily sectionsof the subject, providing a pace signal to assist cardiac operation,etc.) and also measuring one or more electrical characteristics of thesubject (e.g., detecting cardiac electrical activity, measuringimpedance of one or more bodily sections of the subject, etc.).

With respect to performing heart and/or intrathoracic impedance sensingof the subject, note that the such impedance sensing may be implementedin a variety of ways including using implantable electrodes within theheart and/or chest or thorax of the subject or in a noninvasive mannersuch as using electrodes that are in proximity to or in contact with thesurface of the skin of the subject in the general region of the heartand/or chest or thorax of the subject. As the DSCs 28 provide electricalsignaling that is coupled into the body of the subject in the generalregion of the heart and/or chest or thorax of the subject, the DSCs 28are configured to detect impedance and/or impedance change of thosebodily sections of the subject.

There is a correlation between impedance of the heart and/or chest orthorax of the subject and mortality risk. Generally, patients with ahigher impedance of the heart and/or chest or thorax have acorrespondingly lower mortality risk than those with lower orintermediate impedance heart and/or chest or thorax. In addition,monitoring and tracking the trend of the impedance of the heart and/orchest or thorax over time can provide medical professionals valuableinformation regarding the direction of mortality risk of the subject.For example, a baseline measurement of impedance of the heart and/orchest or thorax of a particular subject is made based on a correspondingbill of good health of that subject. Then, over time, such as based onsubsequent office visits of the subject to a medical professional,subsequent measurements of the impedance of the heart and/or chest orthorax of a particular subject are made so that trend tracking of theimpedance of the heart and/or chest or thorax of that particular subjectmay be made over time to provide information to the medical professionalregarding the direction in which the mortality risk of that subject isgoing, whether improving or degrading.

Also, measurement of impedance of the thorax of the subject can alsoprovide indication of heart health including whether or not the subjectis suffering from congestive heart failure. Electrical resistivity,alternatively referred to as specific electrical resistance or volumeresistivity provides a measurement of how strongly a material conductsor impedes electric current applied to it. A material having arelatively low electrical resistivity will allow electric current topass through it relatively easily, whereas a material having arelatively high electrical resistivity will not readily allow electriccurrent passed through it. Electrical resistivity is often representedby the Greek letter p (rho) and is provided in Ohm-meters (Ω-m). Forexample, the electrical resistivity of thoracic tissue may be in therange of ρ=200-5000 Ohm-cm, and the electrical resistivity of blood andfluid may be in the range of ρ=65-150 Ohm-cm. as such, certain bodilysections of a subject with higher blood for fluid content will havecorrespondingly lower impedance.

Providing impedance measurement of heart and/or chest or thorax of thesubject can provide useful information to medical professionals toassess the health of the subject. An impedance measurement of a bodilysection of a subject may alternatively be referred to as the bioimpedance or the bioelectrical impedance of that bodily section of thesubject. By measuring the impedance of the heart and/or chest or thoraxof the subject, a determination of the amount of fluid within the heartand/or chest or thorax of the subject may be made. For example,impedance measurements the heart and/or chest or thorax of the subject(e.g., hemodynamic measurements) in comparison to those measurementsbased on the known ranges of electrical resistivity of thoracic tissuein comparison to the electrical resistivity of blood and fluid (e.g.,blood and fluid having relatively lower electrical resistivity thanthoracic tissue) can provide medical professionals some indication ofthe amount of fluid accumulation in the setting of congestion, such aswith respect to the subject who may be suffering from or trending in thedirection of congestive heart failure. For example, performing trendtracking and impedance (Z) monitoring as a function of time of the heartand/or chest or thorax of the subject is a useful tool for medicalprofessionals to identify the amount of fluid in the heart and/or chestor thorax of the subject.

In addition, note that impedance at a particular location of the subjector with respect to a particular bodily section of the subject may bemade to perform trend tracking and impedance (Z) monitoring as afunction of time, and also note that an impedance profile correspondingto multiple locations of the subject or with respect to a particularbodily section of the subject may alternatively made to in accordancewith performing impedance profile trend tracking and impedance (Z)monitoring as a function of time. Regardless of the particularimplementation by which trend tracking and impedance (Z) monitoring isperformed, whether with respect to one particular electrode, or multipleelectrodes thereby generating an impedance profile, trend tracking andimpedance (Z) monitoring can provide valuable information to medicalprofessionals regarding the health status of the subject. In addition,using one or more DSCs 28 as described herein provides significantimprovement over prior art impedance measurement technology by providingmuch higher precision and accuracy than can be achieved using prior artimpedance measurement technology.

FIGS. 31A and 31B are schematic block diagrams of embodiments 3101 and3102 of trend tracking and impedance (Z) monitoring of one or moreelectrodes to assist in diagnosis of health condition of a subject inaccordance with the present invention. Referring to embodiment 3101 ofFIG. 31A, this diagram shows multiple electrodes (e.g., electrode 1, 2,3, and 4) that are either provisioned individually, such as with respectto FIG. 30, or included within a sheath, such as with respect to FIG.29A, 29B, 29C, or 29D that are operative to facilitate sensing and/orstimulation of one or more bodily sections of the subject. Note that anydifferent number of electrodes may alternatively be used, includingfewer or more than 4 as used in this together diagram. This diagramshows monitoring of the impedance of a number of electrodes (e.g., shownas 4 electrodes in this diagram providing an impedance (Z) profile) atdifferent respective times and comparing the impedance profile of thoserespective electrodes at different times. Such trend tracking andimpedance (Z) monitoring of the electrodes when placed at the samelocations with respect to a subject can provide valuable information tomedical professionals. to determine whether or not, when and identifyingwhether or not a problem exists such as whether or not the mortalityrisk of the subject is improving or degrading, whether or not thesubject is trending towards or away from congestive heart failure, etc.

Examples of such considerations used to determine whether or not aproblem exists with the subject, whether or not the subject is trendingtowards or away from a higher mortality risk, whether or not the subjectis trending towards or away from congestive heart failure, etc. mayinclude any one or more of a trajectory by which the Z profile ischanging, a rate at which the Z profile is changing (e.g., change of theZ profile as a function of time), whether or not the Z profile comparesfavorably with a normal range for that subject, whether or not one ormore of the impedances of the respective electrodes included within theZ profile compare favorably the normal range for that subject, etc.

On the left-hand side of the diagram, at or during time 1, a Z profile 1corresponds to the respective impedances of the electrodes beingmonitored at or during time 1. For example, the impedance of therespective electrodes may be the same or approximately or substantiallythe same (e.g., the same value, or within a certain percentage of beingsame as one another, such as within 1%, 2%, 5%, or some other value). Insome examples, a baseline Z profile for a subject is determined based onthe initial impedances of the electrodes included within the Z profileduring a first office visit of that subject to a medical professional.Such an initial Z profile may correspond to the subject being in goodhealth (e.g., that subject having a bill of good health).

Then, monitoring of one or more characteristics associated with the Zprofile of the subject is performed. Note that the different respectivetimes 1, 2, and so on to n may be uniformly spaced apart, such ascorresponding to different respective office visits to medicalprofessionals on a substantially periodic basis (e.g., every A days,every B weeks, every C months, etc., such that A, B, and C are positiveintegers). However, note that the different respective times 1, 2, andso on to n may not be uniformly spaced apart, and yet may correspond tooffice visits to a medical professional (e.g., time 1 and time 2 spacedapart by 1 month, time 1 and time 2 spaced apart by 8 weeks, etc.).Regardless of how the data is collected, the trend tracking andimpedance (Z) monitoring as performed using the one or more electrodesprovides valuable information to the medical professionals regarding thehealth of the subject including the stability or lack thereof,trajectory, trend, etc. of the health of the subject.

Note that a normal range for that subject for one or more, or all, ofthe respective impedances of the electrodes included within the Zprofile may be defined, and when all, or some acceptable number, of theelectrodes included within the Z profile have impedance values withinthis normal range for the subject (e.g., that subject having a bill ofgood health), then no problem may be identified as existing for thesubject. For example, consider a normal range for that subject extendingfrom a certain percentage greater and less than certain percentage lessthan the baseline/initial impedances of electrodes included within the Zprofile. In one example, consider an upper limit of the normal range forthat subject to be X % greater than the baseline/initial impedances ofelectrodes included within the Z profile and a lower limit of the normalrange for that subject to be Y % less than the baseline/initialimpedances of electrodes included within the Z profile. Consider anexample in which consider an upper limit of the normal range for thatsubject to be 5% greater than the baseline/initial impedances ofelectrodes included within the Z profile and a lower limit of the normalrange for that subject to be 8% less than the baseline/initialimpedances of electrodes included within the Z profile, then the normalrange for that subject would extend from 0.92 to 1.05 of thebaseline/initial impedances of electrodes included within the Z profile.Consider an example in which consider an upper limit of the normal rangefor that subject to be 10% greater than the baseline/initial impedancesof electrodes included within the Z profile and a lower limit of thenormal range for that subject to be 10% less than the baseline/initialimpedances of electrodes included within the Z profile, then the normalrange for that subject would extend from 0.9 to 1.1 of thebaseline/initial impedances of electrodes included within the Z profile.Other values may alternatively be identified for upper and lower limitsof the normal range for that subject in other examples andimplementations based on any number of considerations. Examples of suchconsiderations may be historical or past upper and lower valuesassociated with normal range for the subject (e.g., that subject havinga bill of good health).

Moving to the right in the diagram, consider an example at or duringtime 2 at which the Z profile has modified (e.g., consider Z profile 2at or during time 2 in comparison to Z profile 1 at or during time 1),then a Z profile change a (delta a) may be viewed as a differencebetween the Z profile 2 at or during time 2 in comparison to Z profile 1at or during time 1. For example, consider a situation in which theimpedance of the heart and/or chest or thorax of the subject isdecreasing, such as may be associated with an increase of blood or fluidcontent and any heart and/or chest or thorax of the subject. Consideringthe Z profile 2 at or during time 2, although the respective impedancesof the electrodes included within the Z profile are included within thenormal range for that subject at or during time 2, note that they aremoving in the direction that, if continued, will be approaching thelower limit of the normal range for that subject and possibly expandoutside of the normal range for that subject. This may be indicative ofpossible problems such as an increase of blood or fluid content and anyheart and/or chest or thorax of the subject. For example, the Z profileat time 2, though still within the normal range of that subject, istrending towards decreased impedance that may be indicative of degradinghealth and/or increased mortality risk. Based on this information,medical professionals may initiate a treatment regime for the subject.

This process of monitoring may be continued, such as at or duringdifferent respective times. On the right hand side of the diagram,consider an example at or during some other time, time n, at which the Zprofile has modified even further from a prior time (e.g., consider Zprofile n at or during time n in comparison to Z profile 1 at or duringtime 1 or in comparison to Z profile 2 at or during time 2), then a Zprofile change b (delta b) may be viewed as a difference between the Zprofile 2 at or during time 2 or the Z profile 1 at or during time 1.With respect to the example of this diagram, know that each of therespective impedances of the electrodes included within the Z profileare outside of the normal range for that subject at or during time n.This may be indicative of an actual problems such as an increase ofblood or fluid content and any heart and/or chest or thorax of thesubject. Based on the determination of the existence of a problem basedon the respective impedances of the electrodes included within the Zprofile being outside of the normal range for that subject at or duringtime n, any one or more appropriate actions may be taken by the medicalprofessionals in accordance with providing medical treatment to thesubject. For example, the Z profile at time n, being outside of thenormal range of that subject, may be indicative of very poor healthand/or high mortality risk. Based on this information, medicalprofessionals may initiate more aggressive treatment regime for thesubject including intensifying existing treatment or providing urgentcare as may be needed.

Generally speaking, such Z profile monitoring (e.g., based on theimpedance (Z) (e.g., capacitance) of the respective electrodes includedwithin the Z profile and be monitored to determine any changes as afunction of time. Any one or more determinations may be made based onthe rate of change, the trajectory of change, the direction of change,etc. of the Z profile and/or one or more individual impedances ofelectrodes within the Z profile to facilitate the determination of thestatus, health, etc. of the subject. Note that such determinations mayalso be made based on comparison of one or more characteristicsassociated with the Z profile in comparison to variation fromexpected/historical Z profile of the heart and/or chest or thorax of thesubject.

Referring to embodiment 3102 of FIG. 31B, this diagram shows impedance(Z) monitoring of a singular electrode as may in proximity to or incontact with the subject, which may be implemented individually orwithin the sheath as described herein, etc. This diagram has somesimilarities to the previous diagram with at least one difference beingthat this diagram corresponds to monitoring the impedance of a singleelectrode. For example, this diagram shows an example of tracking andmonitoring the impedance of electrode 1.

At or during a time 1, the impedance of electrode 1 is shown as beingcentered within a normal range for that subject. This impedance may be abaseline impedance of electrode 1 (e.g., an initial impedance such ascorresponding to good health for the subject, such as the subject havinga bill of good health).

At or during a time 2, the impedance of electrode 1 is shown as stillbeing centered within the normal range for that subject, but with aslightly increased impedance yet still being within the normal range forthe subject. In fact, the increase in impedance at this time 2 madecorrespond to an improvement in health of the subject.

At or during a time 3, the impedance of electrode 1 is shown as stillless than at time 2 get still being within the normal range for thatsubject. At or during a time 4, the impedance of electrode 1 is shown asalso being centered within the normal range for that subject (e.g., withapproximately the same impedance measured at time 1).

At or during times 5 and 6, the impedance of electrode 1 is shown asbeing within the normal range for that subject, or at the bottom end ofthe normal range for that subject, with a relatively steep trajectory orfast rate of change and particularly decreasing over time. Thisapproaching the limit of the normal range for that subject, even thoughremaining in the normal range for that subject, may indicate adegradation and health such as an increase in fluid within the heartand/or chest or thorax of the subject, and increased mortality risk,etc. For example, the impedance of electrode 1 at times 5 and 6, thoughstill within the normal range of that subject, is trending towardsdecreased impedance that may be indicative of degrading health and/orincreased mortality risk. Based on this information, medicalprofessionals may initiate a treatment regime for the subject.

At or during a time n, the impedance of electrode 1 is shown as beingoutside of the normal range for that subject. For example, the impedanceof electrode 1, being outside of the normal range of that subject, maybe indicative of very poor health and/or high mortality risk. Based onthis information, medical professionals may initiate more aggressivetreatment regime for the subject including intensifying existingtreatment or providing urgent care as may be needed.

Once a determination is made regarding a problem or a potential problem(e.g., such as associated with swelling, bulging, gas build up, etc.),one or more processing modules is configured to take one or more actionsincluding any of those described above such as based on determination ofa problem with the battery during charging, cease charging of thebattery; alternatively, based on determination of a problem with thebattery during non-charging, provide an error signal to facilitate theuser taking action to remedy or mitigate the problem; shut down one ormore processes or operations of a device in which the battery isimplemented; etc.

FIG. 32 is a schematic block diagram of an embodiment 3200 of a novelelectrocardiogram (ECG) (alternatively referred to as an EKG) machinethat is serviced by DSCs coupled to ECG stickers via electrodes inaccordance with the present invention. This diagram shows an ECG machine3210 that operates using DSCs 28 as described herein instead oftraditional technology employed within prior art ECG machines. Forexample, one or more processing models 42 is in syndication with DSCs 28that respectively service electrodes 1410 that coupled to ECGleads/stickers 3220 that are in contact with the skin surface of asubject in the chest or thorax region. In an example of operation andimplementation, the ECG leads/stickers 3220 are typical ECGleads/stickers that include a mechanism to keep them in place and incontact with the skin surface of the subject (e.g., an adhesive). TheDSCs 28 are configured to detect electrical activity via the ECGleads/stickers 3220. Note that the number of ECG leads/stickers 3220 maybe chosen to be any desired number, and certain applications operateusing 12 ECG leads/stickers 3220. Generally speaking, any desired numberof ECG leads/stickers 3220 may be employed in the given implementation.In one specific example, one (1) single ECG leads/sticker 3220 isemployed and placed on the skin surface of the subject nearest to theheart of the subject.

For example, based on cardiac electrical activity within the cardiacconduction system in accordance with the electrical impulses travelingto the different respective portions of the heart to facilitate beatingof the heart, those electrical impulses are coupled into the ECGleads/stickers 3220 and are then detected by the DSCs 28 via theelectrodes 1410 that couple the DSCs 28 to the ECG leads/stickers 3220.This diagram shows yet another application by which appropriatelyimplemented DSCs 28 may be used to detect electrical activity, namely,cardiac electrical activity within the cardiac conduction system. Fromcertain perspectives, this diagram shows a replacement of existing,prior art ECG machines using DSCs 28 that respectively service ECGleads/stickers 3220 via electrodes 1410.

Note that DSCs 28 as described herein are configured to detectelectrical signals including cardiac electrical activity within thecardiac conduction system of the subject with improved resolution andaccuracy of the electrical response of the heart compared to existing,prior art ECG machines. Also, note that such a replacement of existing,prior art ECG machines using DSCs 28 that respectively service ECGleads/stickers 3220 via electrodes 1410 as described in this diagram maybe realized much more cost effectively than existing, prior art ECGmachines. For example, existing, prior art ECG machines may costanywhere in the range of $1,000s of dollars (e.g., $1,000 to $4,000 oreven more). An implementation as described in this diagram to detectcardiac electrical activity including DSCs 28 that respectively serviceECG leads/stickers 3220 via electrodes 1410 may be realized for afraction of the cost of an existing, prior art ECG machine.

FIG. 33 is a schematic block diagram of an embodiment of another method3300 for execution by one or more devices in accordance with the presentinvention. The method 3300 operates in step 3310 by operating one ormore DSCs for providing one or more signals via one or more electrodesperform sensing and/or stimulation 3310. Note that such sensing and/orstimulation may be performed in accordance with any of a number ofoperations including those described herein. Some examples of suchsensing and or stimulation may include any one or more of pace signaldelivery 3313 such as in accordance with providing electrical impulsesvia a pacemaker implementation to assist in proper cardiac function ofthe subject, servicing of ECG leads/stickers 3312 such as in accordancewith detecting cardiac electrical activity within the cardiac conductionsystem of a subject, operating the one or more DSCs to provide a currentsource signal 3313 such as in accordance with providing electricalstimulus to one or more bodily portions of the subject, operating one ormore DSCs to provide a current sink signal 3314 or treating anabnormally fast heart in a subject suffering from tachycardias,operating the one or more DSCs to detect cardiac electrical activity3315 within the cardiac conduction system of a subject in a manner notspecifically using ECG leads/stickers, operating the one or more DSCs tosense impedance of one or more bodily portions of the subject or toperform trend tracking and impedance (Z) monitoring 3316 of one or morebodily portions of the subject to provide information regarding thehealth status of the subject, and/or any other desired function 3317including those described herein.

The method 3300 also operates in step 3320 by receiving information, viathe one or more DSCs, corresponding to the one or more signals providedvia the one or more electrodes to perform the sensing and orstimulation. In some examples, this information is provided as digitaldata that is generated by the one or more DSCs and is provided to one ormore processing modules. The method 3300 operates in step 3330 byprocessing the information corresponding to the one or more signalsprovided via one or more electrodes to perform the sensing and/orstimulation. In some implementations, such processing in step 3330 isperformed within one or more processing modules.

The method 3300 also operates in step 3340 by determining whether toperform adaptation to the one or more signals provided via the one ormore electrodes to perform the sensing and/or stimulation. Such adetermination may be made based on any of a variety of considerationsincluding favorable or unfavorable comparison to one or more conditions.For example, consider a pacemaker implementation using the one or moreDSCs for providing one or more pace signals via electrodes to facilitateimproved cardiac operation within the subject. Based on the pace signalcharacteristics not facilitating capture thereby initiating a heartbeatin the subject, the pace signal may be adapted in terms of one or moreof its characteristics such as signal magnitude, whether voltage orcurrent, pulse width, etc. thereby tuning the pace signal so as tofacilitate capture by the appropriate portion of the heart of thesubject.

For another example, consider an electrical stimulation implementationusing one or more DSCs for providing one or more electrical signals toan injured bodily portion of the subject to assist in the rehabilitationof the subject. Based on a treatment program failing to producefavorable results, one or more electrical characteristics of the one ormore electric signals may be adapted (e.g., increase signal levels ofthe one or more electric signals, modify frequency of one or moreoscillating components of the one or more electric signals, etc.).

For another example, consider one or more electrical characteristics ofa bodily portion of the subject has changed. Based on detection of thechange of these one or more electrical characteristics of the bodilyportion of the subject, one or more electrical signals may be adaptedbased on the such changes. For example, based on an increased impedanceof the bodily portion of the subject, a signal level that is providing asensing and or stimulation signal to that bodily portion of the subjectmay be increased in response to that increased impedance. Generallyspeaking, a determination to perform adaptation to the one or moresignals provided via one or more electrodes to perform sensing and/orstimulation may be made for based on any desired criterion.

Based on a determination not to perform any adaptation in step 3350, themethod 3300 branches and ends. In an alternative variant of the method3300, based on a determination not to perform any adaptation in step3350, the method 3300 branches and loops back to step 3310. Thisalternative variants of the method 3300 may be viewed as continuing tooperate the one or more DSCs for providing the one more signals via theone or more electrodes to perform sensing and/or stimulation withoutperforming any modification or adaptation to the one or more signals.

Based on the determination to perform adaptation in step 3350, themethod 3300 branches to step 3360 and the method 3300 operates byidentifying one or more electrical characteristics of the one or moresignals to be adapted.

The method 3300 operates in step 3370 by adapting the one or moreelectrical characteristics of the one or more signals that are providedvia one or more electrodes from the one or more DSCs to perform sensingand/or stimulation. Examples of such modification of one or moreelectrical characteristics of the one or more signals may includemodification of any one or more DC level, oscillating componentmagnitude and/or frequency, current level, and/or any other electricalcharacteristic of the one or more signals. In certain examples,adjustment of one or more of the reference signals employed by the oneor more DSCs is performed to effectuate the adaptation of the one ormore electrical characteristics of the one or more signals.

It is noted that terminologies as may be used herein such as bit stream,stream, signal sequence, etc. (or their equivalents) have been usedinterchangeably to describe digital information whose contentcorresponds to any of a number of desired types (e.g., data, video,speech, text, graphics, audio, etc. any of which may generally bereferred to as ‘data’).

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. For some industries, anindustry-accepted tolerance is less than one percent and, for otherindustries, the industry-accepted tolerance is 10 percent or more. Otherexamples of industry-accepted tolerance range from less than one percentto fifty percent. Industry-accepted tolerances correspond to, but arenot limited to, component values, integrated circuit process variations,temperature variations, rise and fall times, thermal noise, dimensions,signaling errors, dropped packets, temperatures, pressures, materialcompositions, and/or performance metrics. Within an industry, tolerancevariances of accepted tolerances may be more or less than a percentagelevel (e.g., dimension tolerance of less than +/−1%). Some relativitybetween items may range from a difference of less than a percentagelevel to a few percent. Other relativity between items may range from adifference of a few percent to magnitude of differences.

As may also be used herein, the term(s) “configured to”, “operablycoupled to”, “coupled to”, and/or “coupling” includes direct couplingbetween items and/or indirect coupling between items via an interveningitem (e.g., an item includes, but is not limited to, a component, anelement, a circuit, and/or a module) where, for an example of indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.

As may even further be used herein, the term “configured to”, “operableto”, “coupled to”, or “operably coupled to” indicates that an itemincludes one or more of power connections, input(s), output(s), etc., toperform, when activated, one or more its corresponding functions and mayfurther include inferred coupling to one or more other items. As maystill further be used herein, the term “associated with”, includesdirect and/or indirect coupling of separate items and/or one item beingembedded within another item.

As may be used herein, the term “compares favorably”, indicates that acomparison between two or more items, signals, etc., provides a desiredrelationship. For example, when the desired relationship is that signal1 has a greater magnitude than signal 2, a favorable comparison may beachieved when the magnitude of signal 1 is greater than that of signal 2or when the magnitude of signal 2 is less than that of signal 1. As maybe used herein, the term “compares unfavorably”, indicates that acomparison between two or more items, signals, etc., fails to providethe desired relationship.

As may be used herein, one or more claims may include, in a specificform of this generic form, the phrase “at least one of a, b, and c” orof this generic form “at least one of a, b, or c”, with more or lesselements than “a”, “b”, and “c”. In either phrasing, the phrases are tobe interpreted identically. In particular, “at least one of a, b, and c”is equivalent to “at least one of a, b, or c” and shall mean a, b,and/or c. As an example, it means: “a” only, “b” only, “c” only, “a” and“b”, “a” and “c”, “b” and “c”, and/or “a”, “b”, and “c”.

As may also be used herein, the terms “processing module”, “processingcircuit”, “processor”, “processing circuitry”, and/or “processing unit”may be a single processing device or a plurality of processing devices.Such a processing device may be a microprocessor, micro-controller,digital signal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on hard coding of thecircuitry and/or operational instructions. The processing module,module, processing circuit, processing circuitry, and/or processing unitmay be, or further include, memory and/or an integrated memory element,which may be a single memory device, a plurality of memory devices,and/or embedded circuitry of another processing module, module,processing circuit, processing circuitry, and/or processing unit. Such amemory device may be a read-only memory, random access memory, volatilememory, non-volatile memory, static memory, dynamic memory, flashmemory, cache memory, and/or any device that stores digital information.Note that if the processing module, module, processing circuit,processing circuitry, and/or processing unit includes more than oneprocessing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,processing circuitry and/or processing unit implements one or more ofits functions via a state machine, analog circuitry, digital circuitry,and/or logic circuitry, the memory and/or memory element storing thecorresponding operational instructions may be embedded within, orexternal to, the circuitry comprising the state machine, analogcircuitry, digital circuitry, and/or logic circuitry. Still further notethat, the memory element may store, and the processing module, module,processing circuit, processing circuitry and/or processing unitexecutes, hard coded and/or operational instructions corresponding to atleast some of the steps and/or functions illustrated in one or more ofthe Figures. Such a memory device or memory element can be included inan article of manufacture.

One or more embodiments have been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claims. Further, the boundariesof these functional building blocks have been arbitrarily defined forconvenience of description. Alternate boundaries could be defined aslong as the certain significant functions are appropriately performed.Similarly, flow diagram blocks may also have been arbitrarily definedherein to illustrate certain significant functionality.

To the extent used, the flow diagram block boundaries and sequence couldhave been defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claims. One of average skill in the art will alsorecognize that the functional building blocks, and other illustrativeblocks, modules and components herein, can be implemented as illustratedor by discrete components, application specific integrated circuits,processors executing appropriate software and the like or anycombination thereof.

In addition, a flow diagram may include a “start” and/or “continue”indication. The “start” and “continue” indications reflect that thesteps presented can optionally be incorporated in or otherwise used inconjunction with one or more other routines. In addition, a flow diagrammay include an “end” and/or “continue” indication. The “end” and/or“continue” indications reflect that the steps presented can end asdescribed and shown or optionally be incorporated in or otherwise usedin conjunction with one or more other routines. In this context, “start”indicates the beginning of the first step presented and may be precededby other activities not specifically shown. Further, the “continue”indication reflects that the steps presented may be performed multipletimes and/or may be succeeded by other activities not specificallyshown. Further, while a flow diagram indicates a particular ordering ofsteps, other orderings are likewise possible provided that theprinciples of causality are maintained.

The one or more embodiments are used herein to illustrate one or moreaspects, one or more features, one or more concepts, and/or one or moreexamples. A physical embodiment of an apparatus, an article ofmanufacture, a machine, and/or of a process may include one or more ofthe aspects, features, concepts, examples, etc. described with referenceto one or more of the embodiments discussed herein. Further, from figureto figure, the embodiments may incorporate the same or similarly namedfunctions, steps, modules, etc. that may use the same or differentreference numbers and, as such, the functions, steps, modules, etc. maybe the same or similar functions, steps, modules, etc. or differentones.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of one or more of theembodiments. A module implements one or more functions via a device suchas a processor or other processing device or other hardware that mayinclude or operate in association with a memory that stores operationalinstructions. A module may operate independently and/or in conjunctionwith software and/or firmware. As also used herein, a module may containone or more sub-modules, each of which may be one or more modules.

As may further be used herein, a computer readable memory includes oneor more memory elements. A memory element may be a separate memorydevice, multiple memory devices, or a set of memory locations within amemory device. Such a memory device may be a read-only memory, randomaccess memory, volatile memory, non-volatile memory, static memory,dynamic memory, flash memory, cache memory, a quantum register or otherquantum memory and/or any other device that stores data in anon-transitory manner. Furthermore, the memory device may be in a formof a solid-state memory, a hard drive memory or other disk storage,cloud memory, thumb drive, server memory, computing device memory,and/or other non-transitory medium for storing data. The storage of dataincludes temporary storage (i.e., data is lost when power is removedfrom the memory element) and/or persistent storage (i.e., data isretained when power is removed from the memory element). As used herein,a transitory medium shall mean one or more of: (a) a wired or wirelessmedium for the transportation of data as a signal from one computingdevice to another computing device for temporary storage or persistentstorage; (b) a wired or wireless medium for the transportation of dataas a signal within a computing device from one element of the computingdevice to another element of the computing device for temporary storageor persistent storage; (c) a wired or wireless medium for thetransportation of data as a signal from one computing device to anothercomputing device for processing the data by the other computing device;and (d) a wired or wireless medium for the transportation of data as asignal within a computing device from one element of the computingdevice to another element of the computing device for processing thedata by the other element of the computing device. As may be usedherein, a non-transitory computer readable memory is substantiallyequivalent to a computer readable memory. A non-transitory computerreadable memory can also be referred to as a non-transitory computerreadable storage medium.

While particular combinations of various functions and features of theone or more embodiments have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent disclosure is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

What is claimed is:
 1. A pacemaker system comprising: a drive-sensecircuit (DSC) operably coupled to a pacemaker lead, wherein the DSC isoperably coupled and configured to receive a reference signal and togenerate a pace signal including electrical impulses based on thereference signal, wherein, when enabled, the DSC configured to: providethe pace signal via the pacemaker lead to an electrically responsiveportion of a cardiac conductive system of a subject to facilitatecardiac operation of a cardiovascular system of the subject, whereinmuscles of a heart of the subject produce a mechanical response to theelectrical impulses of the pace signal to move blood through thecardiovascular system of the subject; sense, via the pacemaker lead,cardiac electrical activity of the cardiovascular system of the subjectthat is generated in response to the pace signal and that iselectrically coupled into the pacemaker lead; and generate a digitalsignal that is representative of the cardiac electrical activity of thecardiovascular system of the subject that is sensed via the pacemakerlead; memory that stores operational instructions; and one or moreprocessing modules operably coupled to the DSC and the memory, wherein,when enabled, the one or more processing modules is configured toexecute the operational instructions to: generate the reference signal;and process the digital signal generated by the DSC to determine thecardiac electrical activity of the cardiovascular system of the subjectthat is sensed via the pacemaker lead.
 2. The pacemaker system of claim1, wherein the pacemaker lead is implanted in or in proximity to asinoatrial (SA) node of the cardiovascular system of the subject, andwherein the pacemaker lead is implemented with one single conductor. 3.The pacemaker system of claim 1, wherein the pacemaker lead is implantedin or in proximity to a ventricle of the cardiovascular system of thesubject, and wherein the pacemaker lead is implemented with one singleconductor.
 4. The pacemaker system of claim 1, wherein, when enabled,the one or more processing modules is further configured to execute theoperational instructions to: adjust one or more electricalcharacteristics of the reference signal to facilitate generation of thepace signal by the DSC to facilitate capture by the cardiac conductivesystem of the subject in response to the pace signal.
 5. The pacemakersystem of claim 4, wherein adjustment of the one or more electricalcharacteristics of the reference signal causes adjustment of at leastone electrical characteristic of the pace signal including at least oneof: a magnitude of the electrical impulses of the pace signal; a pulsewidth of the electrical impulses of the pace signal; an amount ofcurrent level delivered via the electrical impulses of the pace signal;or a frequency or rate of the electrical impulses of the pace signal. 6.The pacemaker system of claim 1, wherein, when enabled, the one or moreprocessing modules is further configured to execute the operationalinstructions to: process the digital signal generated by the DSC todetermine the cardiac electrical activity of the cardiovascular systemof the subject that is sensed via the pacemaker lead including todetermine whether there is capture by the cardiac conductive system ofthe subject in response to the pace signal; and based on a determinationthat there is no capture by the cardiac conductive system of thesubject, adjust one or more electrical characteristics of the referencesignal to facilitate generation of the pace signal by the DSC tofacilitate capture by the cardiac conductive system of the subject inresponse to the pace signal.
 7. The pacemaker system of claim 6, whereinadjustment of the one or more electrical characteristics of thereference signal causes adjustment of at least one electricalcharacteristic of the pace signal including at least one of: a magnitudeof the electrical impulses of the pace signal; a pulse width of theelectrical impulses of the pace signal; an amount of current leveldelivered via the electrical impulses of the pace signal; or a frequencyor rate of the electrical impulses of the pace signal.
 8. The pacemakersystem of claim 1, wherein the DSC further comprises: a comparatorconfigured to produce an error signal based on comparison of thereference signal to the pace signal, wherein the reference signal isreceived at a first input of the comparator, and the pace signal isreceived at a second input of the comparator; a dependent current supplyconfigured to generate the pace signal based on the error signal and toprovide the pace signal via a single line that couples to the pacemakerlead and the second input of the comparator; and an analog to digitalconverter (ADC) configured to process the error signal to generate thedigital signal that is representative of the cardiac electrical activityof the cardiovascular system of the subject that is sensed via thepacemaker lead.
 9. The pacemaker system of claim 8, wherein, whenenabled, the one or more processing modules is further configured toexecute the operational instructions to: adjust a programmable gain ofthe dependent current supply, wherein scaling the programmable gain ofthe dependent current supply provides for scaling of the error signal.10. The pacemaker system of claim 1, wherein the DSC further comprises:a power source circuit operably coupled via a single line to thepacemaker lead, wherein, when enabled, the power source circuit isconfigured to provide an analog signal via the single line coupling tothe pacemaker lead, and wherein the analog signal includes at least oneof a DC (direct current) component or an oscillating component; and apower source change detection circuit operably coupled to the powersource circuit, wherein, when enabled, the power source change detectioncircuit is configured to: detect an effect on the analog signal that isbased on at least one of an electrical characteristic of the pacemakerlead or the cardiac electrical activity of the cardiovascular system ofthe subject that is sensed via the pacemaker lead; and generate thedigital signal that is representative of the cardiac electrical activityof the cardiovascular system of the subject that is sensed via thepacemaker lead.
 11. The pacemaker system of claim 10 further comprising:the power source circuit including a power source to source at least oneof a voltage or a current via the single line to the pacemaker lead; andthe power source change detection circuit including: a power sourcereference circuit configured to provide at least one of a voltagereference or a current reference; and a comparator configured to comparethe at least one of the voltage or the current provided via the singleline to the pacemaker lead to the at least one of the voltage referenceor the current reference to produce the analog signal.
 12. A method forexecution by a pacemaker system, the method comprising: operating adrive-sense circuit (DSC), operably coupled to a pacemaker leadimplemented with one single conductor, to receive a reference signal andto generate a pace signal including electrical impulses based on thereference signal, wherein the pacemaker lead is implanted in or inproximity to a sinoatrial (SA) node or a ventricle of a cardiovascularsystem of a subject; operating the DSC to provide the pace signal fromthe DSC via the pacemaker lead to an electrically responsive portion ofa cardiac conductive system of the subject to facilitate cardiacoperation of the cardiovascular system of the subject, wherein musclesof a heart of the subject produce a mechanical response to theelectrical impulses of the pace signal to move blood through thecardiovascular system of the subject; operating the DSC to sense, viathe pacemaker lead, cardiac electrical activity of the cardiovascularsystem of the subject that is generated in response to the pace signaland that is electrically coupled into the pacemaker lead; generating adigital signal that is representative of the cardiac electrical activityof the cardiovascular system of the subject that is sensed via thepacemaker lead; and processing the digital signal generated by the DSCto determine the cardiac electrical activity of the cardiovascularsystem of the subject that is sensed via the pacemaker lead.
 13. Themethod of claim 12 further comprising: adjusting one or more electricalcharacteristics of the reference signal to facilitate generation of thepace signal by the DSC to facilitate capture by the cardiac conductivesystem of the subject in response to the pace signal.
 14. The method ofclaim 13, wherein adjustment of the one or more electricalcharacteristics of the reference signal causes adjustment of at leastone electrical characteristic of the pace signal including at least oneof: a magnitude of the electrical impulses of the pace signal; a pulsewidth of the electrical impulses of the pace signal; an amount ofcurrent level delivered via the electrical impulses of the pace signal;or a frequency or rate of the electrical impulses of the pace signal.15. The method of claim 12 further comprising: processing the digitalsignal generated by the DSC to determine the cardiac electrical activityof the cardiovascular system of the subject that is sensed via thepacemaker lead including to determine whether there is capture by thecardiac conductive system of the subject in response to the pace signal;and based on a determination that there is no capture by the cardiacconductive system of the subject, adjusting one or more electricalcharacteristics of the reference signal to facilitate generation of thepace signal by the DSC to facilitate capture by the cardiac conductivesystem of the subject in response to the pace signal.
 16. The method ofclaim 15, wherein adjustment of the one or more electricalcharacteristics of the reference signal causes adjustment of at leastone electrical characteristic of the pace signal including at least oneof: a magnitude of the electrical impulses of the pace signal; a pulsewidth of the electrical impulses of the pace signal; an amount ofcurrent level delivered via the electrical impulses of the pace signal;or a frequency or rate of the electrical impulses of the pace signal.17. The method of claim 12, wherein the DSC further comprises: acomparator configured to produce an error signal based on comparison ofthe reference signal to the pace signal, wherein the reference signal isreceived at a first input of the comparator, and the pace signal isreceived at a second input of the comparator; a dependent current supplyconfigured to generate the pace signal based on the error signal and toprovide the pace signal via a single line that couples to the pacemakerlead and the second input of the comparator; and an analog to digitalconverter (ADC) configured to process the error signal to generate thedigital signal that is representative of the cardiac electrical activityof the cardiovascular system of the subject that is sensed via thepacemaker lead.
 18. The method of claim 17 further comprising: adjustinga programmable gain of the dependent current supply, wherein scaling theprogrammable gain of the dependent current supply provides for scalingof the error signal.
 19. The method of claim 12, wherein the DSC furthercomprises: a power source circuit operably coupled via a single line tothe pacemaker lead, wherein, when enabled, the power source circuit isconfigured to provide an analog signal via the single line coupling tothe pacemaker lead, and wherein the analog signal includes at least oneof a DC (direct current) component or an oscillating component; and apower source change detection circuit operably coupled to the powersource circuit, wherein, when enabled, the power source change detectioncircuit is configured to: detect an effect on the analog signal that isbased on at least one of an electrical characteristic of the pacemakerlead or the cardiac electrical activity of the cardiovascular system ofthe subject that is sensed via the pacemaker lead; and generate thedigital signal that is representative of the cardiac electrical activityof the cardiovascular system of the subject that is sensed via thepacemaker lead.
 20. The method of claim 19 further comprising: the powersource circuit including a power source to source at least one of avoltage or a current via the single line to the pacemaker lead; and thepower source change detection circuit including: a power sourcereference circuit configured to provide at least one of a voltagereference or a current reference; and a comparator configured to comparethe at least one of the voltage or the current provided via the singleline to the pacemaker lead to the at least one of the voltage referenceor the current reference to produce the analog signal.